Mediterranean climate
Encyclopedia
A Mediterranean climate is the climate
typical of most of the lands in the Mediterranean Basin
, and is a particular variety of subtropical climate. The lands around the Mediterranean Sea form the largest area where this climate type is found, but it also prevails in much of California
, in parts of Western
and South Australia
, in southwestern South Africa
, sections of Central Asia
, and in parts of central coastal Chile
.
, South Atlantic High
, and Indian Ocean high. These high pressure cells shift towards the poles in the summer and towards the equator in the winter, playing a major role in the formation of the world's tropical deserts and the Mediterranean Basin's climate.
The South Atlantic High is similarly associated with the Namib Desert
and the Mediterranean climate of the western part of South Africa. The North Pacific High is related to the Sonoran Desert
and California's climate, while the South Pacific High is related to the Atacama Desert
and central Chile's climate, and the Indian Ocean High is related to the deserts of western Australia (Great Sandy Desert
, Great Victoria Desert
, and Gibson Desert
) and the Mediterranean climate of southwest and south-central Australia.
Most large, historic cities of the Mediterranean basin, including Athens
, Algiers
, Barcelona
, Beirut
, İzmir
, Jerusalem, Marseille
, Rome
and Tunis
, lie within Mediterranean climatic zones, as do major cities outside of the Mediterranean basin, such as Lisbon
, Casablanca
, Cape Town
, Adelaide
, Perth
, Los Angeles
, San Francisco, Santiago de Chile
, Tashkent
, and Dushanbe
.
, "dry-summer subtropical" climates (classified as Csa and Csb) are often referred to as "Mediterranean". Under the Köppen-Geiger system, "C" zones have an average temperature above 10 °C (50 °F) in their warmest months, and an average in the coldest between 18 °C (64 °F) and −3 °C. (26.6 °F) (or, in some applications, between 20 °C and 0 °C (32 °F)). The second letter indicates the precipitation pattern: "s" represents dry summers: first, Köppen has defined a dry month as a month with less than one-third that of the wettest winter month, and with less than 30 mm of precipitations in a summer month. Some, however, use a 40 mm level. The third letter indicates the degree of summer heat: "a" represents an average temperature in the warmest month above 22 °C (72 °F), with at least four months averaging above 10 °C (50 °F); "b", an average temperature in the warmest month below 22 °C, and again with at least two months averaging above 10 °C.
Under this classification, dry-summer subtropical climates (Csa, Csb) usually occur on the western sides of continents. Csb zones include areas normally associated with Oceanic
climates, not Mediterranean, such as much of the Pacific Northwest
, much of southern Chile
, parts of west-central Argentina
, northern Portugal
and, north-western Spain
. Additional highland areas in the subtropics also meet Cs requirements, though they, too, are not normally associated with Mediterranean climates, as do a number of oceanic islands such as Madeira
, the Juan Fernández Islands
, the western part of the Canary Islands
and the eastern part of the Azores
.
Under Trewartha's modified Koeppen climate classification, the two major requirements for a Cs climate are revised. Under Trewartha's system, at least eight months must have average temperatures of at least 10 °C, and the average annual precipitation must not exceed 900 mm (35 in). Thus, under this system, many Csb zones (including the Pacific Northwest), become DO Oceanic.
of varying humidity and making rainfall impossible or unlikely except for the occasional thunderstorm
, while during winter the polar
jet stream
and associated periodic storms reach into the lower latitude
s of the Mediterranean zones, bringing rain, with snow at higher elevations. As a result, areas with this climate receive almost all of their yearly rainfall during their winter season, and may go anywhere from 4 to 6 months during the summer without having any significant precipitation
.
Toward the equatorial latitudes, winter precipitation decreases as a share of annual precipitation as the climate grades equatorward into the steppe climate usually characterized as BSHs normally too dry to support unirrigated agriculture. Toward the polar latitudes, total moisture usually increases; in Europe there is more summer rain further north while along the American west coast the winters become more intensely wet and the dry seasons shorter as one moves north. In the northwestern Mediterranean Basin
, the rainiest season is divided into a primary maximum during the autumn and a secondary in spring, making for a shorter dry season than in the classic Mediterranean climate.
The majority of the regions with Mediterranean climates have relatively mild winters and very warm summers. However winter and summer temperatures can vary greatly between different regions with a Mediterranean climate. In the case of winters for instance, Lisbon
experiences very mild temperatures in the winter, with frost and snow practically unknown, whereas Thessaloniki
has colder winters with annual frosts and snowfall. In the case of summers for instance, Athens experiences rather high temperatures in the summer (48.0°C has been measured in nearby Eleusina
). In contrast, San Francisco has mild summers due to the upwelling
of cold subsurface waters along the coast producing regular summer fog that does not reach far inland; Sacramento
, roughly 150 km to the northeast and beyond hills that stop any onshore breeze or summer fog, has frequent summer high temperatures near 40°C.
Because most regions with a Mediterranean climate are near large bodies of water, temperature
s are generally moderate with a comparatively small range of temperatures between the winter low and summer high (although the daily range of temperature during the summer is large due to dry and clear conditions, except along the immediate coasts). Temperatures during winter only occasionally fall below the freezing point and snow
generally is seldom seen. In the summer, the temperatures range from mild to very hot, depending on distance from a large body of water, elevation, and latitude. Even in the warmest locations with a Mediterranean-type climate, however, temperatures usually do not reach the highest readings found in adjacent desert
regions because of cooling from water bodies, although strong winds from inland desert regions can sometimes boost summer temperatures, quickly increasing the risk of Wildfires.
As in every climatologic domain, the highland locations of the Mediterranean domain can present cooler temperatures in winter than the lowland areas, temperatures which can sometimes prohibit the growth of typical Mediterranean plants. Some Spanish authors opt to use the term "Continental Mediterranean climate" for some regions with lower temperature in winter than the coastal areas (direct translation from Clima Mediterráneo Continentalizado), but most climate classifications (including Köppen's Cs zones) show no distinction.
Additionally, the temperature and rainfall pattern for a Csa or even a Csb climate can exist as a microclimate in some high-altitude locations adjacent to a rare tropical As (summer-drought tropical climate, typically in a rainshadow region).
biome
is closely associated with Mediterranean climate zones. Particularly distinctive of the climate are sclerophyll
shrublands, called maquis
in the Mediterranean Basin, chaparral
in California, matorral
in Chile, fynbos
in South Africa, and mallee
and kwongan
shrublands in Australia. Aquatic
communities in Mediterranean climate regions are adapted to a yearly cycle in which abiotic (environmental) controls of stream populations and community structure dominate during floods, Biotic component
(e.g. competition and predation) controls become increasingly important as the discharge declines, and environmental controls regain dominance as environmental conditions become very harsh (i.e. hot and dry); as a result, these communities are well suited to recover from droughts, floods, and fires.
Much native vegetation in Mediterranean climate area valleys have been cleared for agriculture. In places such as the Sacramento Valley
and Oxnard Plain
in California
, draining marshes and estuaries combined with supplemental irrigation has led to a century of intensive agriculture. Much of the Overberg
in the southern Cape of South Africa
, once covered with renosterveld
, has likewise been largely converted to agriculture, mainly wheat
. In hillside and mountainous areas, away from urban sprawl
, ecosystems and habitats of native vegetation are more sustained.
The fynbos
vegetation in the South-western Cape in South Africa is famed for its high floral diversity, and includes such plant types as members of the Restionaceae
, Erica
s (Heaths) and Protea
s. Representatives of the Proteaceae
also grow in Australia, such as Banksia
s.
The palette of California native plants
is also renowned for its species
and cultivar
diversity.
Csa climates are mainly found around the Mediterranean Sea
, southwestern Australia
, southwestern South Africa
and in the interior of California
.
As stated earlier, in some instances, regions with this subtype of the Mediterranean climate closely resembles an Oceanic climate
. Unlike typical Mediterranean climates, for the majority of the year, these regions experience generally cloudier and damper conditions. However, sunshine duration remains higher than in the Cfb areas, and during the summer months, these regions experience sunny, dry and warm conditions, where almost no rain falls. There is the legitimate threat of forest fires in these areas, in regions such as Galicia and the Pacific Northwest
. Despite the fact that these climates are technically Csb climates, a number of scientists (and others) do not consider the climate “Mediterranean”, primarily because of the predominantly oceanic characteristics that these places exhibit. They are instead categorized as a form of an oceanic climate.
Csb climates are found in northwestern Iberia
, coastal California
and parts of the Pacific Northwest
, central Chile
, parts of southern Australia
and sections of southwestern South Africa
.
Climate
Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...
typical of most of the lands in the Mediterranean Basin
Mediterranean Basin
In biogeography, the Mediterranean Basin refers to the lands around the Mediterranean Sea that have a Mediterranean climate, with mild, rainy winters and hot, dry summers, which supports characteristic Mediterranean forests, woodlands, and scrub vegetation...
, and is a particular variety of subtropical climate. The lands around the Mediterranean Sea form the largest area where this climate type is found, but it also prevails in much of California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, in parts of Western
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
and South Australia
South Australia
South Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent; with a total land area of , it is the fourth largest of Australia's six states and two territories.South Australia shares borders with all of the mainland...
, in southwestern South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
, sections of Central Asia
Central Asia
Central Asia is a core region of the Asian continent from the Caspian Sea in the west, China in the east, Afghanistan in the south, and Russia in the north...
, and in parts of central coastal Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
.
Characteristics
The climate is characterized by warm to hot, dry summers and mild to cool, wet winters. Mediterranean climate zones are associated with the five large subtropical high pressure cells of the oceans, the Azores HighAzores High
The Azores High is a large subtropical semi-permanent centre of high atmospheric pressure found near the Azores in the Atlantic Ocean, at the Horse latitudes...
, South Atlantic High
South Atlantic High
South Atlantic High is a semipermanent pressure high centered at about 25°S, 15°W, in the Atlantic Ocean. It is also called the St. Helena High. It can stretch thousands of miles across the South Atlantic affecting shipping. Sailors try to find a "corridor" through using the low pressure systems...
, and Indian Ocean high. These high pressure cells shift towards the poles in the summer and towards the equator in the winter, playing a major role in the formation of the world's tropical deserts and the Mediterranean Basin's climate.
The South Atlantic High is similarly associated with the Namib Desert
Namib Desert
The Namib Desert is a desert in Namibia and southwest Angola that forms part of the Namib-Naukluft National Park, the largest game reserve in Africa. The name "Namib" is of Nama origin and means "vast place"...
and the Mediterranean climate of the western part of South Africa. The North Pacific High is related to the Sonoran Desert
Sonoran Desert
The Sonoran Desert is a North American desert which straddles part of the United States-Mexico border and covers large parts of the U.S. states of Arizona and California and the northwest Mexican states of Sonora, Baja California, and Baja California Sur. It is one of the largest and hottest...
and California's climate, while the South Pacific High is related to the Atacama Desert
Atacama Desert
The Atacama Desert is a plateau in South America, covering a strip of land on the Pacific coast, west of the Andes mountains. It is, according to NASA, National Geographic and many other publications, the driest desert in the world...
and central Chile's climate, and the Indian Ocean High is related to the deserts of western Australia (Great Sandy Desert
Great Sandy Desert
The Great Sandy Desert is a desert located in the North West of Western Australia straddling the Pilbara and southern Kimberley regions. It is the second largest desert in Australia after the Great Victoria Desert and encompasses an area of...
, Great Victoria Desert
Great Victoria Desert
The Great Victoria Desert is a barren and sparsely populated desert area of southern Australia.-Location and description:The Great Victoria is the biggest desert in Australia and consists of many small sandhills, grassland plains, areas with a closely packed surface of pebbles and salt lakes...
, and Gibson Desert
Gibson Desert
The Gibson Desert covers a large dry area in the state of Western Australia and is still largely in an almost "pristine" state. It is about in size, making it the 5th largest desert in Australia, after the Great Sandy, Great Victoria, Tanami and Simpson deserts.-Location and description:The Gibson...
) and the Mediterranean climate of southwest and south-central Australia.
Most large, historic cities of the Mediterranean basin, including Athens
Athens
Athens , is the capital and largest city of Greece. Athens dominates the Attica region and is one of the world's oldest cities, as its recorded history spans around 3,400 years. Classical Athens was a powerful city-state...
, Algiers
Algiers
' is the capital and largest city of Algeria. According to the 1998 census, the population of the city proper was 1,519,570 and that of the urban agglomeration was 2,135,630. In 2009, the population was about 3,500,000...
, Barcelona
Barcelona
Barcelona is the second largest city in Spain after Madrid, and the capital of Catalonia, with a population of 1,621,537 within its administrative limits on a land area of...
, Beirut
Beirut
Beirut is the capital and largest city of Lebanon, with a population ranging from 1 million to more than 2 million . Located on a peninsula at the midpoint of Lebanon's Mediterranean coastline, it serves as the country's largest and main seaport, and also forms the Beirut Metropolitan...
, İzmir
Izmir
Izmir is a large metropolis in the western extremity of Anatolia. The metropolitan area in the entire Izmir Province had a population of 3.35 million as of 2010, making the city third most populous in Turkey...
, Jerusalem, Marseille
Marseille
Marseille , known in antiquity as Massalia , is the second largest city in France, after Paris, with a population of 852,395 within its administrative limits on a land area of . The urban area of Marseille extends beyond the city limits with a population of over 1,420,000 on an area of...
, Rome
Rome
Rome is the capital of Italy and the country's largest and most populated city and comune, with over 2.7 million residents in . The city is located in the central-western portion of the Italian Peninsula, on the Tiber River within the Lazio region of Italy.Rome's history spans two and a half...
and Tunis
Tunis
Tunis is the capital of both the Tunisian Republic and the Tunis Governorate. It is Tunisia's largest city, with a population of 728,453 as of 2004; the greater metropolitan area holds some 2,412,500 inhabitants....
, lie within Mediterranean climatic zones, as do major cities outside of the Mediterranean basin, such as Lisbon
Lisbon
Lisbon is the capital city and largest city of Portugal with a population of 545,245 within its administrative limits on a land area of . The urban area of Lisbon extends beyond the administrative city limits with a population of 3 million on an area of , making it the 9th most populous urban...
, Casablanca
Casablanca
Casablanca is a city in western Morocco, located on the Atlantic Ocean. It is the capital of the Grand Casablanca region.Casablanca is Morocco's largest city as well as its chief port. It is also the biggest city in the Maghreb. The 2004 census recorded a population of 2,949,805 in the prefecture...
, Cape Town
Cape Town
Cape Town is the second-most populous city in South Africa, and the provincial capital and primate city of the Western Cape. As the seat of the National Parliament, it is also the legislative capital of the country. It forms part of the City of Cape Town metropolitan municipality...
, Adelaide
Adelaide
Adelaide is the capital city of South Australia and the fifth-largest city in Australia. Adelaide has an estimated population of more than 1.2 million...
, Perth
Perth, Western Australia
Perth is the capital and largest city of the Australian state of Western Australia and the fourth most populous city in Australia. The Perth metropolitan area has an estimated population of almost 1,700,000....
, Los Angeles
Los Ángeles
Los Ángeles is the capital of the province of Biobío, in the commune of the same name, in Region VIII , in the center-south of Chile. It is located between the Laja and Biobío rivers. The population is 123,445 inhabitants...
, San Francisco, Santiago de Chile
Santiago, Chile
Santiago , also known as Santiago de Chile, is the capital and largest city of Chile, and the center of its largest conurbation . It is located in the country's central valley, at an elevation of above mean sea level...
, Tashkent
Tashkent
Tashkent is the capital of Uzbekistan and of the Tashkent Province. The officially registered population of the city in 2008 was about 2.2 million. Unofficial sources estimate the actual population may be as much as 4.45 million.-Early Islamic History:...
, and Dushanbe
Dushanbe
-Economy:Coal, lead, and arsenic are mined nearby in the cities of Nurek and Kulob allowing for the industrialization of Dushanbe. The Nurek Dam, the world's highest as of 2008, generates 95% of Tajikistan's electricity, and another dam, the Roghun Dam, is planned on the Vakhsh River...
.
Köppen climate classification
Under the Köppen climate classificationKöppen climate classification
The Köppen climate classification is one of the most widely used climate classification systems. It was first published by Crimea German climatologist Wladimir Köppen in 1884, with several later modifications by Köppen himself, notably in 1918 and 1936...
, "dry-summer subtropical" climates (classified as Csa and Csb) are often referred to as "Mediterranean". Under the Köppen-Geiger system, "C" zones have an average temperature above 10 °C (50 °F) in their warmest months, and an average in the coldest between 18 °C (64 °F) and −3 °C. (26.6 °F) (or, in some applications, between 20 °C and 0 °C (32 °F)). The second letter indicates the precipitation pattern: "s" represents dry summers: first, Köppen has defined a dry month as a month with less than one-third that of the wettest winter month, and with less than 30 mm of precipitations in a summer month. Some, however, use a 40 mm level. The third letter indicates the degree of summer heat: "a" represents an average temperature in the warmest month above 22 °C (72 °F), with at least four months averaging above 10 °C (50 °F); "b", an average temperature in the warmest month below 22 °C, and again with at least two months averaging above 10 °C.
Under this classification, dry-summer subtropical climates (Csa, Csb) usually occur on the western sides of continents. Csb zones include areas normally associated with Oceanic
Oceanic climate
An oceanic climate, also called marine west coast climate, maritime climate, Cascadian climate and British climate for Köppen climate classification Cfb and subtropical highland for Köppen Cfb or Cwb, is a type of climate typically found along the west coasts at the middle latitudes of some of the...
climates, not Mediterranean, such as much of the Pacific Northwest
Pacific Northwest
The Pacific Northwest is a region in northwestern North America, bounded by the Pacific Ocean to the west and, loosely, by the Rocky Mountains on the east. Definitions of the region vary and there is no commonly agreed upon boundary, even among Pacific Northwesterners. A common concept of the...
, much of southern Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
, parts of west-central Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
, northern Portugal
Portugal
Portugal , officially the Portuguese Republic is a country situated in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of Europe, and is bordered by the Atlantic Ocean to the West and South and by Spain to the North and East. The Atlantic archipelagos of the...
and, north-western Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
. Additional highland areas in the subtropics also meet Cs requirements, though they, too, are not normally associated with Mediterranean climates, as do a number of oceanic islands such as Madeira
Madeira
Madeira is a Portuguese archipelago that lies between and , just under 400 km north of Tenerife, Canary Islands, in the north Atlantic Ocean and an outermost region of the European Union...
, the Juan Fernández Islands
Juan Fernández Islands
The Juan Fernández Islands are a sparsely inhabited island group reliant on tourism and fishing in the South Pacific Ocean, situated about off the coast of Chile, and is composed of three main volcanic islands; Robinson Crusoe Island, Alejandro Selkirk Island and Santa Clara Island, the first...
, the western part of the Canary Islands
Canary Islands
The Canary Islands , also known as the Canaries , is a Spanish archipelago located just off the northwest coast of mainland Africa, 100 km west of the border between Morocco and the Western Sahara. The Canaries are a Spanish autonomous community and an outermost region of the European Union...
and the eastern part of the Azores
Azores
The Archipelago of the Azores is composed of nine volcanic islands situated in the middle of the North Atlantic Ocean, and is located about west from Lisbon and about east from the east coast of North America. The islands, and their economic exclusion zone, form the Autonomous Region of the...
.
Under Trewartha's modified Koeppen climate classification, the two major requirements for a Cs climate are revised. Under Trewartha's system, at least eight months must have average temperatures of at least 10 °C, and the average annual precipitation must not exceed 900 mm (35 in). Thus, under this system, many Csb zones (including the Pacific Northwest), become DO Oceanic.
Precipitation
During summer, regions of Mediterranean climate are dominated by subtropical high pressure cells, with dry sinking air capping a surface marine layerMarine layer
A marine layer is an air mass which develops over the surface of a large body of water such as the ocean or large lake in the presence of a temperature inversion. The inversion itself is usually initiated by the cooling effect of the water on the surface layer of an otherwise warm air mass...
of varying humidity and making rainfall impossible or unlikely except for the occasional thunderstorm
Thunderstorm
A thunderstorm, also known as an electrical storm, a lightning storm, thundershower or simply a storm is a form of weather characterized by the presence of lightning and its acoustic effect on the Earth's atmosphere known as thunder. The meteorologically assigned cloud type associated with the...
, while during winter the polar
Polar region
Earth's polar regions are the areas of the globe surrounding the poles also known as frigid zones. The North Pole and South Pole being the centers, these regions are dominated by the polar ice caps, resting respectively on the Arctic Ocean and the continent of Antarctica...
jet stream
Jet stream
Jet streams are fast flowing, narrow air currents found in the atmospheres of some planets, including Earth. The main jet streams are located near the tropopause, the transition between the troposphere and the stratosphere . The major jet streams on Earth are westerly winds...
and associated periodic storms reach into the lower latitude
Latitude
In geography, the latitude of a location on the Earth is the angular distance of that location south or north of the Equator. The latitude is an angle, and is usually measured in degrees . The equator has a latitude of 0°, the North pole has a latitude of 90° north , and the South pole has a...
s of the Mediterranean zones, bringing rain, with snow at higher elevations. As a result, areas with this climate receive almost all of their yearly rainfall during their winter season, and may go anywhere from 4 to 6 months during the summer without having any significant precipitation
Precipitation (meteorology)
In meteorology, precipitation In meteorology, precipitation In meteorology, precipitation (also known as one of the classes of hydrometeors, which are atmospheric water phenomena is any product of the condensation of atmospheric water vapor that falls under gravity. The main forms of precipitation...
.
Toward the equatorial latitudes, winter precipitation decreases as a share of annual precipitation as the climate grades equatorward into the steppe climate usually characterized as BSHs normally too dry to support unirrigated agriculture. Toward the polar latitudes, total moisture usually increases; in Europe there is more summer rain further north while along the American west coast the winters become more intensely wet and the dry seasons shorter as one moves north. In the northwestern Mediterranean Basin
Mediterranean Basin
In biogeography, the Mediterranean Basin refers to the lands around the Mediterranean Sea that have a Mediterranean climate, with mild, rainy winters and hot, dry summers, which supports characteristic Mediterranean forests, woodlands, and scrub vegetation...
, the rainiest season is divided into a primary maximum during the autumn and a secondary in spring, making for a shorter dry season than in the classic Mediterranean climate.
Temperature
Lisbon
Lisbon is the capital city and largest city of Portugal with a population of 545,245 within its administrative limits on a land area of . The urban area of Lisbon extends beyond the administrative city limits with a population of 3 million on an area of , making it the 9th most populous urban...
experiences very mild temperatures in the winter, with frost and snow practically unknown, whereas Thessaloniki
Thessaloniki
Thessaloniki , historically also known as Thessalonica, Salonika or Salonica, is the second-largest city in Greece and the capital of the region of Central Macedonia as well as the capital of the Decentralized Administration of Macedonia and Thrace...
has colder winters with annual frosts and snowfall. In the case of summers for instance, Athens experiences rather high temperatures in the summer (48.0°C has been measured in nearby Eleusina
Eleusina
Eleusina is a town and municipality in West Attica, Greece. It is situated about 18 km northwest from the centre of Athens. It is located in the Thriasian Plain, at the northernmost end of the Saronic Gulf. It is the seat of administration of West Attica regional unit...
). In contrast, San Francisco has mild summers due to the upwelling
Upwelling
Upwelling is an oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water towards the ocean surface, replacing the warmer, usually nutrient-depleted surface water. The increased availability in upwelling regions results in high levels of primary...
of cold subsurface waters along the coast producing regular summer fog that does not reach far inland; Sacramento
Sacramento, California
Sacramento is the capital city of the U.S. state of California and the county seat of Sacramento County. It is located at the confluence of the Sacramento River and the American River in the northern portion of California's expansive Central Valley. With a population of 466,488 at the 2010 census,...
, roughly 150 km to the northeast and beyond hills that stop any onshore breeze or summer fog, has frequent summer high temperatures near 40°C.
Because most regions with a Mediterranean climate are near large bodies of water, temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
s are generally moderate with a comparatively small range of temperatures between the winter low and summer high (although the daily range of temperature during the summer is large due to dry and clear conditions, except along the immediate coasts). Temperatures during winter only occasionally fall below the freezing point and snow
Snow
Snow is a form of precipitation within the Earth's atmosphere in the form of crystalline water ice, consisting of a multitude of snowflakes that fall from clouds. Since snow is composed of small ice particles, it is a granular material. It has an open and therefore soft structure, unless packed by...
generally is seldom seen. In the summer, the temperatures range from mild to very hot, depending on distance from a large body of water, elevation, and latitude. Even in the warmest locations with a Mediterranean-type climate, however, temperatures usually do not reach the highest readings found in adjacent desert
Desert
A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than...
regions because of cooling from water bodies, although strong winds from inland desert regions can sometimes boost summer temperatures, quickly increasing the risk of Wildfires.
As in every climatologic domain, the highland locations of the Mediterranean domain can present cooler temperatures in winter than the lowland areas, temperatures which can sometimes prohibit the growth of typical Mediterranean plants. Some Spanish authors opt to use the term "Continental Mediterranean climate" for some regions with lower temperature in winter than the coastal areas (direct translation from Clima Mediterráneo Continentalizado), but most climate classifications (including Köppen's Cs zones) show no distinction.
Additionally, the temperature and rainfall pattern for a Csa or even a Csb climate can exist as a microclimate in some high-altitude locations adjacent to a rare tropical As (summer-drought tropical climate, typically in a rainshadow region).
Mediterranean Biome
The Mediterranean forests, woodlands, and scrubMediterranean forests, woodlands, and scrub
Mediterranean forests, woodlands, and scrub biome, defined by the World Wildlife Fund, characterized by dry summers and rainy winters. Summers are typically hot in low-lying inland locations but can be cool near some seas, as near San Francisco, which have a sea of cool waters...
biome
Biome
Biomes are climatically and geographically defined as similar climatic conditions on the Earth, such as communities of plants, animals, and soil organisms, and are often referred to as ecosystems. Some parts of the earth have more or less the same kind of abiotic and biotic factors spread over a...
is closely associated with Mediterranean climate zones. Particularly distinctive of the climate are sclerophyll
Sclerophyll
Sclerophyll is the term for a type of vegetation that has hard leaves and short internodes . The word comes from the Greek sclero and phyllon ....
shrublands, called maquis
Maquis shrubland
thumb|220px|Low Maquis in Corsica.220px|thumb|High macchia in Sardinia.Maquis or macchia is a shrubland biome in the Mediterranean region, typically consisting of densely growing evergreen shrubs such as holm oak, tree heath, strawberry tree, sage, juniper, buckthorn, spurge olive and myrtle...
in the Mediterranean Basin, chaparral
Chaparral
Chaparral is a shrubland or heathland plant community found primarily in the U.S. state of California and in the northern portion of the Baja California peninsula, Mexico...
in California, matorral
Chilean Matorral
The Chilean Matorral is a terrestrial ecoregion of central Chile, located on the west coast of South America. It is in the Mediterranean forests, woodlands, and scrub biome, part of the Neotropic ecozone....
in Chile, fynbos
Fynbos
Fynbos is the natural shrubland or heathland vegetation occurring in a small belt of the Western Cape of South Africa, mainly in winter rainfall coastal and mountainous areas with a Mediterranean climate...
in South Africa, and mallee
Mallee Woodlands and Shrublands
Mallee Woodlands and Shrublands is a Major Vegetation Group which occurs in semi-arid areas of southern Australia. The vegetation is dominated by mallee eucalypts which are rarely over 6 metres high...
and kwongan
Kwongan
Kwongan is a type of heathland found on the coastal plains of Western Australia. The name is derived from the language of the Noongar people. Kwongan comprises floristically-rich heath with dense thickets of sclerophyllous shrubs and isolated small trees...
shrublands in Australia. Aquatic
Aquatic ecosystem
An aquatic ecosystem is an ecosystem in a body of water. Communities of organisms that are dependent on each other and on their environment live in aquatic ecosystems. The two main types of aquatic ecosystems are marine ecosystems and freshwater ecosystems....
communities in Mediterranean climate regions are adapted to a yearly cycle in which abiotic (environmental) controls of stream populations and community structure dominate during floods, Biotic component
Biotic component
Biotic components are the living things that shape an ecosystem. A biotic factor is any living component that affects another organism, including animals that consume the organism in question, and the living food that the organism consumes. Each biotic factor needs energy to do work and food for...
(e.g. competition and predation) controls become increasingly important as the discharge declines, and environmental controls regain dominance as environmental conditions become very harsh (i.e. hot and dry); as a result, these communities are well suited to recover from droughts, floods, and fires.
Natural vegetation
The native vegetation of Mediterranean climate lands must be adapted to survive long, hot summer droughts and prolonged wet periods in winter. Mediterranean vegetation examples include the following:- Evergreen trees: such as PinePinePines are trees in the genus Pinus ,in the family Pinaceae. They make up the monotypic subfamily Pinoideae. There are about 115 species of pine, although different authorities accept between 105 and 125 species.-Etymology:...
s, CypressCypressCypress is the name applied to many plants in the cypress family Cupressaceae, which is a conifer of northern temperate regions. Most cypress species are trees, while a few are shrubs...
es, and OakOakAn oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...
s - Deciduous trees: such as Sycamores, OakOakAn oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...
s, and BuckeyesAesculus californicaAesculus californica is a species of buckeye that is native [ |] to California and southwest Oregon [Jackson, County], and the only buckeye native to these states.-Description:... - Fruit trees such as OliveOliveThe olive , Olea europaea), is a species of a small tree in the family Oleaceae, native to the coastal areas of the eastern Mediterranean Basin as well as northern Iran at the south end of the Caspian Sea.Its fruit, also called the olive, is of major agricultural importance in the...
s, FigsCommon figThe Common fig is a deciduous tree growing to heights of up to 6 m in the genus Ficus from the family Moraceae known as Common fig tree. It is a temperate species native to the Middle East.-Description:...
, CitrusCitrusCitrus is a common term and genus of flowering plants in the rue family, Rutaceae. Citrus is believed to have originated in the part of Southeast Asia bordered by Northeastern India, Myanmar and the Yunnan province of China...
, WalnutsJuglans californicaJuglans californica, the California black walnut, also called the California walnut, or the Southern California black walnut, is a large shrub or small tree of the Juglandaceae family endemic to California....
and Grapes - Shrubs: Bay laurelBay LaurelThe bay laurel , also known as sweet bay, bay tree, true laurel, Grecian laurel, laurel tree, or simply laurel, is an aromatic evergreen tree or large shrub with green, glossy leaves, native to the Mediterranean region. It is the source of the bay leaf used in cooking...
, ericaEricaErica ,the heaths or heathers, is a genus of approximately 860 species of flowering plants in the family Ericaceae. The English common names "heath" and "heather" are shared by some closely related genera of similar appearance....
s, banksiaBanksiaBanksia is a genus of around 170 species in the plant family Proteaceae. These Australian wildflowers and popular garden plants are easily recognised by their characteristic flower spikes and fruiting "cones" and heads. When it comes to size, banksias range from prostrate woody shrubs to trees up...
s, and ChamiseAdenostoma fasciculatumAdenostoma fasciculatum is a flowering plant native to California and northern Baja California. This shrub is one of the most widespread plants of the chaparral biome.-Description:... - Sub-shrubs: such as SagesLamiaceaeThe mints, taxonomically known as Lamiaceae or Labiatae, are a family of flowering plants. They have traditionally been considered closely related to Verbenaceae, but in the 1990s, phylogenetic studies suggested that many genera classified in Verbenaceae belong instead in Lamiaceae...
, Artemisias, and Sagebrush - Grasses: Grassland types, Themeda triandraThemeda triandraThemeda triandra is a perennial grass widespread in Africa, Australia, Asia and the Pacific. In Australia it is commonly known as kangaroo grass, in East and South Africa it is known as "red oat grass" or red grass, in Afrikaans, rooigras.The species has a tuffted habit and can reach up to 1.5 m...
, Bunchgrasses; SedgesCarexCarex is a genus of plants in the family Cyperaceae, commonly known as sedges. Other members of the Cyperaceae family are also called sedges, however those of genus Carex may be called "true" sedges, and it is the most species-rich genus in the family. The study of Carex is known as...
, and RushesJuncaceaeJuncaceae, the rush family, are a monocotyledonous family of flowering plants. There are eight genera and about 400 species. Members of the Juncaceae are slow-growing, rhizomatous, herbaceous plants, and they may superficially resemble grasses. They often grow on infertile soils in a wide range... - Herbs: such as fragrant RosemaryRosemaryRosemary, , is a woody, perennial herb with fragrant, evergreen, needle-like leaves and white, pink, purple or blue flowers, native to the Mediterranean region. It is a member of the mint family Lamiaceae, which includes many other herbs, and is one of two species in the genus Rosmarinus...
, ThymeThymeThyme is a culinary and medicinal herb of the genus Thymus.-History:Ancient Egyptians used thyme for embalming. The ancient Greeks used it in their baths and burnt it as incense in their temples, believing it was a source of courage...
, and LavenderLavenderThe lavenders are a genus of 39 species of flowering plants in the mint family, Lamiaceae. An Old World genus, distributed from Macaronesia across Africa, the Mediterranean, South-West Asia, Arabia, Western Iran and South-East India...
Much native vegetation in Mediterranean climate area valleys have been cleared for agriculture. In places such as the Sacramento Valley
Sacramento Valley
The Sacramento Valley is the portion of the California Central Valley that lies to the north of the San Joaquin-Sacramento Delta in the U.S. state of California. It encompasses all or parts of ten counties.-Geography:...
and Oxnard Plain
Oxnard Plain
The Oxnard Plain is a large coastal plain in southwest Ventura County, California bounded by the Santa Monica Mountains, the Santa Susana Mountains, and Oak Ridge to the east, the Topatopa Mountains to the north, the Santa Clara River Valley to the northeast and the Pacific Ocean to the south and...
in California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, draining marshes and estuaries combined with supplemental irrigation has led to a century of intensive agriculture. Much of the Overberg
Overberg
Overberg is a district in South Africa to the east of Cape Town beyond the Hottentots-Holland mountains. It lies along the Cape Province's south coast between the Cape Peninsula and the region known as the Garden Route in the east...
in the southern Cape of South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
, once covered with renosterveld
Renosterveld
Renosterveld is a term used for one of the major plant communities and vegetation types of the Cape Floristic Region which is located in southwestern and southeastern South Africa, in southernmost Africa...
, has likewise been largely converted to agriculture, mainly wheat
Wheat
Wheat is a cereal grain, originally from the Levant region of the Near East, but now cultivated worldwide. In 2007 world production of wheat was 607 million tons, making it the third most-produced cereal after maize and rice...
. In hillside and mountainous areas, away from urban sprawl
Urban sprawl
Urban sprawl, also known as suburban sprawl, is a multifaceted concept, which includes the spreading outwards of a city and its suburbs to its outskirts to low-density and auto-dependent development on rural land, high segregation of uses Urban sprawl, also known as suburban sprawl, is a...
, ecosystems and habitats of native vegetation are more sustained.
The fynbos
Fynbos
Fynbos is the natural shrubland or heathland vegetation occurring in a small belt of the Western Cape of South Africa, mainly in winter rainfall coastal and mountainous areas with a Mediterranean climate...
vegetation in the South-western Cape in South Africa is famed for its high floral diversity, and includes such plant types as members of the Restionaceae
Restionaceae
Restionaceae, also called restiads, is the botanical name for a family of rush-like flowering plants native to the Southern Hemisphere.- Description :...
, Erica
Erica
Erica ,the heaths or heathers, is a genus of approximately 860 species of flowering plants in the family Ericaceae. The English common names "heath" and "heather" are shared by some closely related genera of similar appearance....
s (Heaths) and Protea
Protea
Protea is both the botanical name and the English common name of a genus of flowering plants, sometimes also called sugarbushes.-Etymology:...
s. Representatives of the Proteaceae
Proteaceae
Proteaceae is a family of flowering plants distributed in the Southern Hemisphere. The family comprises about 80 genera with about 1600 species. Together with the Platanaceae and Nelumbonaceae they make up the order Proteales. Well known genera include Protea, Banksia, Embothrium, Grevillea,...
also grow in Australia, such as Banksia
Banksia
Banksia is a genus of around 170 species in the plant family Proteaceae. These Australian wildflowers and popular garden plants are easily recognised by their characteristic flower spikes and fruiting "cones" and heads. When it comes to size, banksias range from prostrate woody shrubs to trees up...
s.
The palette of California native plants
California native plants
California native plants are plants that existed in California prior to the arrival of European explorers and colonists in the late 18th century...
is also renowned for its species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
and cultivar
Cultivar
A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...
diversity.
Hot-summer Mediterranean climate
This subtype of the Mediterranean climate (Csa) is the most common form of the Mediterranean climate, therefore it is also known as “Typical Mediterranean climate”. As stated earlier, regions with this form of a Mediterranean climate experiences average monthly temperatures in excess of 21.8°C (72°F) during its warmest month and an average in the coldest month between 18°C (64°F) and −3°C (26.6°F) or, in some applications, between 18°C and 0°C (32°F). Also, at least four months must average above 10°C (50°F). Regions with this form of the Mediterranean climate typically experience hot, sometimes very hot and dry summers and mild, wet winters. In a number of instances, summers here can closely resemble summers seen in arid and semiarid climates. However, high temperatures during summers are generally not quite as high as those seen in arid or semiarid climates due to the presence of a large body of water. All areas with this subtype have wet winters. However, some areas with a hot Mediterranean subtype can actually experience very chilly winters, complete with occasional snowfall. Precipitation is heavier during the colder months. However, there are a number of clear, sunny days during the wetter months.Csa climates are mainly found around the Mediterranean Sea
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
, southwestern Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, southwestern South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
and in the interior of California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
.
Warm-summer Mediterranean climate
Occasionally also termed “Cool-summer Mediterranean climate”, this subtype of the Mediterranean climate (Csb) is the less common form of the Mediterranean climate. As stated earlier, regions with this subtype of the Mediterranean climate experiences warm (but not hot) and dry summers, with no average monthly temperatures above 21.8°C (72°F) during its warmest month and an average in the coldest month between 18°C (64°F) and −3°C (26.6°F) or, in some applications, between 18°C and 0°C (32°F). Also, at least four months must average above 10°C (50°F). Winters are rainy and can be mild to chilly. In a few instances, snow can fall on these areas. Precipitation is heavier during the colder months, but there are a number of clear sunny days even during the wetter seasons.As stated earlier, in some instances, regions with this subtype of the Mediterranean climate closely resembles an Oceanic climate
Oceanic climate
An oceanic climate, also called marine west coast climate, maritime climate, Cascadian climate and British climate for Köppen climate classification Cfb and subtropical highland for Köppen Cfb or Cwb, is a type of climate typically found along the west coasts at the middle latitudes of some of the...
. Unlike typical Mediterranean climates, for the majority of the year, these regions experience generally cloudier and damper conditions. However, sunshine duration remains higher than in the Cfb areas, and during the summer months, these regions experience sunny, dry and warm conditions, where almost no rain falls. There is the legitimate threat of forest fires in these areas, in regions such as Galicia and the Pacific Northwest
Pacific Northwest
The Pacific Northwest is a region in northwestern North America, bounded by the Pacific Ocean to the west and, loosely, by the Rocky Mountains on the east. Definitions of the region vary and there is no commonly agreed upon boundary, even among Pacific Northwesterners. A common concept of the...
. Despite the fact that these climates are technically Csb climates, a number of scientists (and others) do not consider the climate “Mediterranean”, primarily because of the predominantly oceanic characteristics that these places exhibit. They are instead categorized as a form of an oceanic climate.
Csb climates are found in northwestern Iberia
Iberian Peninsula
The Iberian Peninsula , sometimes called Iberia, is located in the extreme southwest of Europe and includes the modern-day sovereign states of Spain, Portugal and Andorra, as well as the British Overseas Territory of Gibraltar...
, coastal California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
and parts of the Pacific Northwest
Pacific Northwest
The Pacific Northwest is a region in northwestern North America, bounded by the Pacific Ocean to the west and, loosely, by the Rocky Mountains on the east. Definitions of the region vary and there is no commonly agreed upon boundary, even among Pacific Northwesterners. A common concept of the...
, central Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
, parts of southern Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
and sections of southwestern South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
.