Desert climate

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Locations of deserts. Outside of the polar regions, deserts typically feature arid climates.

Under the Koppen climate classification, a Desert climate (BWh, BWk, BWn), also known as an arid climate, is a climate where temperatures are moderate and rainfall is too low to sustain any vegetation at all, or at best a very scanty scrub. Areas featuring this climate are usually deserts. An area that features this climate typically experiences less than 250 mm (10 inches) per year of rainfall and in some years may experience no precipitation at all. In some instances an area may experience slightly more than 250 mm of precipitation annually; but is still considered a desert climate due to the fact that the region loses more water via evapotranspiration than falls as precipitation. There are generally three variations of a desert climate; a hot desert climate (BWh), a cold desert climate (BWk) and a mild desert climate (sometimes labeled BWn).

[edit] Hot desert climates

Hot desert climates are typically found in the subtropics where there is unbroken sunshine for the whole year due to the stable descending air and high pressure. Such areas include the Sahara, Saudi Arabia, large parts of Iran and Iraq, northwest India, southwestern United States, Northern Mexico, South Africa and much of Australia. Here, maximum temperatures of 40°C to 45°C are usually common, although during colder periods of the year, night-time temperatures can drop to freezing or below due to the exceptional radiation loss under the clear skies. However, very rarely do temperatures drop far below freezing in areas featuring a hot desert climate.

Notable cities with a hot desert climate

• Cairo, Egypt
• Khartoum, Sudan
• Riyadh, Saudi Arabia
• Kuwait City, Kuwait
• Dubai, UAE
• Abu Dhabi, UAE
• Baghdad, Iraq
• Manama, Bahrain
• Doha, Qatar
• Muscat, Oman
• Tehran, Iran
• Karachi, Pakistan
• Ashgabat, Turkmenistan
• Alice Springs, Australia
• Ciudad Juarez, Mexico
• Hermosillo, Mexico
• Mexicali, Mexico
• Phoenix, USA
• Las Vegas, USA
• El Paso, USA

[edit] Cold desert climates

This variant of the desert climate is somewhat rare. A cold desert climate is typically found in temperate zones, almost always in the rain shadow of high mountains which restrict precipitation from the westerly winds, or in the case of Central Asia, from the monsoon.

Cold desert climates feature hot (sometimes exceptionally hot) and dry summers, though its summers typically are not quite as hot as summers in hot desert climates. Unlike hot desert climates, cold desert climates can feature brutally cold, dry winters with temperatures far below the freezing point. The Gobi desert in Mongolia is an example where a cold desert climate exists. Though hot in summer, it shares the very cold winters of central Asia. Argentine Patagonia is another major example of a BWk climate. Though not quite as cold as the Gobi Desert in the winter, the rain shadow of the Andes creates extremely dry and windy conditions in the Patagonia.

The Arctic and Antarctic regions also receive very little precipitation during the year, owing to the exceptionally cold dry air, but are more usually classified as types of polar climates.

Notable cities with a cold desert climate

• Ulan Bator, Mongolia
• Urumqi, China
• Kashgar, China
• Comodoro Rivadavia, Argentina

[edit] Mild desert climates

This variant of a desert climate is extremely rare. Mild desert climates are usually found along the west coasts of continents at tropical or near-tropical locations, though they can also be found at higher altitudes at these locations.

Mild desert climates are characterized by cooler temperatures than encountered elsewhere at comparable latitudes (usually due to the nearby presence of cold ocean currents) and frequent fog and low clouds, despite the fact that these places can rank among the driest on earth in terms of actual precipitation received. Temperatures are mild throughout the year, usually not subject to any of the temperature extremes typically found in desert climates.

Notable cities with a mild desert climate

• Lima, Peru
• Sanaa, Yemen
• Walvis Bay, Namibia

[edit] Charts of Selected Cities

[edit] Hot Desert Climates

[edit] Cold Desert Climates

[edit] Mild Desert Climates

[edit] References

• http://www.ace.mmu.ac.uk/eae/Climate/Older/Desert_Climate.html
• http://www.blueplanetbiomes.org/desert.htm