Temperature

Mediterranean Climate Distribution in the Americas All regions with Mediterranean climates have relatively mild winters, but summer temperatures are variable depending on the region. For instance, Athens, Greece experiences rather high temperatures in the summer (48.0 °C has been measured in Eleusina), whereas San Francisco has cool, mild summers due to the upwelling of ...

Temperature

Mediterranean Climate Distribution in the Americas All regions with Mediterranean climates have relatively mild winters, but summer temperatures are variable depending on the region. For instance, Athens, Greece experiences rather high temperatures in the summer (48.0 °C has been measured in Eleusina), whereas San Francisco has cool, mild summers due to the upwelling of cold subsurface waters along the coast. Because all 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 temperatures during the summer is large, except along the immediate coasts due to dry and clear conditions). Temperatures during winter only occasionally reach freezing and snow only rarely occurs at sea level, but often in surrounding mountains due to wet conditions. In the summer, the temperatures range from mild to very warm, depending on distance from the open ocean, elevation, and latitude. Even in the warmest locations with a Mediterranean-type climate, however, temperatures usually don't reach the highest readings found in adjacent desert regions due to cooling from water bodies, although strong winds from inland desert regions can sometimes boost summer temperatures quickly resulting in a much increased forest fire risk.

Inland locations sheltered from or distant from sea breezes can experience severe heat during the summer. Locations inside the Sacramento Valley of northern California, for example, are subject to summer temperatures characteristic of hot deserts (often around 40°C/104F), although winters are rainy enough to allow lusher vegetation than is typical in deserts. Unlike the coastal climates that are designated Csb in the Köppen climate classification—characteristic of places with cooler summers—the hotter, typically inland areas have the Csa classification that indicates a hot summer. Porto, Portugal, experiences the typical Mediterranean pattern of cool, rainy winters and very dry summers, but has relatively mild average summer temperatures.

On another note, locations that are slightly higher latitude or elevation and are cut off from milder ocean winds may have somewhat colder winters and more distinct seasons with occasional snow. This "temperate Mediterranean" climate is most noticeable in the Rogue and Umpqua Basins of southwestern Oregon, central Spain, southeastern France away from the immediate coastline, northern Italy, and northern Greece. In these areas, plants that are commonly associated with milder Mediterranean climates, such as citrus can be frozen to death in a severe winter and are thus not part of the regular landscape.

Areas of high altitude adjacent to locations with Mediterranean climates, such as the "Mesetas" or plateaus of central Spain, may have the cold winters that are characteristic of a continental climate (see Continental Mediterranean climate); under Köppen's scheme such places might earn the designation Dsa (at lower latitudes above Csa), Dsb (either at high elevations in the lower latitudes or at lower elevations in the mid-latitudes above Csb) or even Dsc (just below the tree line). An example of a very humid Mediterranean Snow climate Dfsc is the highest summit on Orjen, Zubacki kabao in the subadriatic Dinaric Alps in Montenegro.