Desert climate

The typically bald, rocky, or sandy surfaces in desert climates are dry and hold little moisture, quickly evaporating the already little rainfall they receive.

Although no part of Earth is known for certain to be rainless, in the Atacama Desert of northern Chile, the average annual rainfall over 17 years was only 5 millimetres (0.20 in).

In these locations, stable descending air and high pressure aloft clear clouds and create hot, arid conditions with intense sunshine.

Hot desert climates are found across vast areas of North Africa, West Asia, northwestern parts of the Indian Subcontinent, southwestern Africa, interior Australia, the Southwestern United States, northern Mexico, sections of southeastern Spain, the coast of Peru, and Chile.

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.

[5][6] Hot deserts are lands of extremes: most of them are among the hottest, the driest, and the sunniest places on Earth because of nearly constant high pressure; the almost permanent removal of low-pressure systems, dynamic fronts, and atmospheric disturbances; sinking air motion; dry atmosphere near the surface and aloft; the exacerbated exposure to the sun where solar angles are always high makes this desert inhospitable to most species.

Cold desert climates are typically located in temperate zones in the 30s and 40s latitudes, usually in the leeward rain shadow of high mountains, restricting precipitation from the westerly winds.

The Hautes Plaines, located in the northeastern section of Morocco and in Algeria, is another prominent example of a cold desert climate.

These areas are generally classified as having polar climates because they have average summer temperatures below 10 °C (50 °F) even if they have some characteristics of extreme non-polar deserts.