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Mediterranean climate
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For the influence of Mediterranean climates on viticulture, see Mediterranean climate (wine).

Areas with a Mediterranean climate
A Mediterranean climate is the climate typical of the lands in theMediterranean 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 andSouth Australia, in southwestern South Africa, sections of Central Asia, and in parts of central coastal Chile. Contents [hide] * 1 Köppen climate classification * 2 Precipitation * 3 Temperature * 4 Mediterranean Biome * 4.1 Natural vegetation * 5 Hot-summer Mediterranean climate * 6 Warm-summer Mediterranean climate * 7 See also * 8 References * 9 External links |
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Köppen climate classification[edit]
Under the Köppen climate classification, "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 to −3 °C (64 to 27 °F) (or, in some applications, between 20 to 0 °C (68 to 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 precipitation in a summer month. Some, however, use a 40 mm level.[1][2] 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.[3] 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 Köppen 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 millimetres (35 in). Thus, under this system, many Csbzones (including the Pacific Northwest) become DO Oceanic.
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Precipitation[edit] “ | It [Chile] has four months of winter, no more, and in them, except when there is a quarter moon, when it rains one or two days, all the other days have such beautiful suns... | ” | —Pedro de Valdivia to Charles V, Holy Roman Emperor |
During summer, regions of Mediterranean climate are dominated by subtropical high pressure cells, with dry sinking air capping a surface marine layer 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 latitudes of the Mediterranean zones, bringing rain, with snow at higher elevations. As a result, areas with this climate receive almost all of their precipitation during their winter season, and may go anywhere from 4 to 6 months during the summer without having any significantprecipitation.
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Temperature[edit]

Mediterranean Climate Distribution in the Americas
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 Madrid has colder winters with annual frosts and snowfall. In the case of summers for instance, Athens experiences rather high temperatures in the summer (48 °C (118 °F) 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.
Because most regions with a Mediterranean climate are near large bodies of water, temperatures 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 is generally 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[4] (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 tropicalAs (summer-drought tropical climate, typically in a rainshadow region).
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Mediterranean Biome[edit]
The Mediterranean forests, woodlands, and scrub biome is closely associated with Mediterranean climate zones. Particularly distinctive of the climate are sclerophyllshrublands, 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.[5]
Natural vegetation[edit]
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:[6] * Evergreen trees: such as Pines, Cypresses, and Oaks * Deciduous trees: such as Sycamores, Oaks, and Buckeyes * Fruit trees such as Olives, Figs, Citrus, Walnuts and Grapes * Shrubs: Bay laurel, ericas, banksias, and Chamise * Sub-shrubs: such as Sages, Artemisias, and Sagebrush * Grasses: Grassland types, Themeda triandra, Bunchgrasses; Sedges, and Rushes * Herbs: such as fragrant Rosemary, Thyme, and Lavender.
Much native vegetation in Mediterranean climate area valleys have been cleared for agriculture. In places such as the Sacramento Valley and Oxnard Plain inCalifornia, 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 fromurban 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,Ericas (Heaths) and Proteas. Representatives of the Proteaceae also grow in Australia, such as Banksias. The palette of California native plants is also renowned for its species and cultivar diversity.
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Hot-summer Mediterranean climate[edit]

Hot-summer Mediterranean climate (Csa)
This subtype of the Mediterranean climate (Csa) is the most common form of the Mediterranean climate, therefore it is also known as a “typical Mediterranean climate”. As stated earlier, regions with this form of a Mediterranean climate experience average monthly temperatures in excess of 22.0 °C (71.6 °F) during its warmest month and an average in the coldest month between 18 to −3 °C (64 to 27 °F) or, in some applications, between 18 to 0 °C (64 to 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, southwestern Australia, southwestern South Africa, sections of Central Asia and in the interior of California. Southern California's coasts also experience hot summers due to the shielding effect of the Channel Islands. Rome | Climate chart (explanation) | J | F | M | A | M | J | J | A | S | O | N | D | 103 123 | 99 134 | 68 155 | 65 188 | 48 2311 | 34 2715 | 23 3017 | 33 3018 | 68 2715 | 94 2211 | 130 167 | 111 134 | Average max. and min. temperatures in °C | Precipitation totals in mm | Source: [7] | | [show]Imperial conversion | |

Los Angeles | Climate chart (explanation) | J | F | M | A | M | J | J | A | S | O | N | D | 85 209 | 94 2110 | 80 2111 | 21 2312 | 7.9 2414 | 1.5 2616 | 0.3 2918 | 3.3 2919 | 8.1 2918 | 9.4 2616 | 27 2311 | 49 209 | Average max. and min. temperatures in °C | Precipitation totals in mm | Source: NOAA | | [show]Imperial conversion | |

Perth | Climate chart (explanation) | J | F | M | A | M | J | J | A | S | O | N | D | 9.5 3118 | 13 3118 | 19 3016 | 44 2614 | 118 2211 | 177 199 | 170 188 | 134 198 | 81 2010 | 52 2311 | 22 2614 | 13 2916 | Average max. and min. temperatures in °C | Precipitation totals in mm | Source: BoM[8] | | [show]Imperial conversion | |
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Warm-summer Mediterranean climate[edit]

Warm-summer Mediterranean climate (Csb)
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 experience warm (but not hot) and dry summers, with no average monthly temperatures above 22.0 °C(71.6 °F) during its warmest month and an average in the coldest month between 18 to −3 °C (64 to 27 °F) or, in some applications, between 18 to 0 °C (64 to 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 resemble 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[9] and the Pacific Northwest.[10] 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 ofoceanic 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. Porto | Climate chart (explanation) | J | F | M | A | M | J | J | A | S | O | N | D | 158 145 | 140 156 | 90 177 | 116 189 | 98 2011 | 46 2314 | 18 2516 | 27 2515 | 71 2415 | 138 2012 | 158 178 | 195 157 | Average max. and min. temperatures in °C | Precipitation totals in mm | Source: Instituto de Meteorologia[11] | | [show]Imperial conversion | |

San Francisco | Climate chart (explanation) | J | F | M | A | M | J | J | A | S | O | N | D | 120 158 | 105 169 | 86 1710 | 32 1810 | 14 1911 | 3.3 2012 | 1 2012 | 2.3 2113 | 7.1 2213 | 30 2113 | 84 1810 | 81 158 | Average max. and min. temperatures in °C | Precipitation totals in mm | Source: NOAA[12] | | [show]Imperial conversion | |

Cape Town | Climate chart (explanation) | J | F | M | A | M | J | J | A | S | O | N | D | 15 2616 | 17 2716 | 20 2514 | 41 2312 | 69 209 | 93 188 | 82 187 | 77 188 | 40 199 | 30 2111 | 14 2413 | 17 2515 | Average max. and min. temperatures in °C | Precipitation totals in mm | Source: WMO[13] | | [show]Imperial conversion | |
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See also
Wine regions with Mediterranean climates[edit] * Tuscany and most other Italian wine regions * Most Greek wine regions * Most Israeli wine regions * Most Lebanese wine regions * Most Montenegrin wine regions * Southern Rhone Valley * Catalonia * Languedoc * Provence * Coastal Portuguese wine region * Primorska Slovenian wine region * Coastal Croatian wine regions * Napa Valley and other coastal California wine regions * Texas Hill Country and Texas High Plains * Western Australia and South Australia wine regions * Chilean Central Valley * Coastal South African wine regions * Western coastal Turkish wine regions