Tropical Desert Climate (BWh)

Latitude/Longitude: 27.7^o N; 8.1^o W
Average Annual Temperature (^oC) = 22.8
Annual Temperature Range (^oC) = 21.2
Total Annual Precipitation (mm) = 43.8
Summer Precipitation (mm) =11.8
Winter Precipitation (mm) = 32

Caravan of camels in the Grand Erg Desert of Algeria.

Photo credit: J. Van Acker, FAO #17902
Used with permission

Geographic Distribution

• coastal Chile and Peru

• southern Argentina

• southwest Africa

• north Africa

• Arabia, Iran

• Pakistan, and western India;

• Baja California and interior Mexico

Controlling Factors

• Descending, diverging, circulation of subtropical highs

• Continentality linked often with rain shadow location.

• cT air masses

Characteristics

• Among the driest places on earth

• Mean annual temperature above 64.4^o F (18^oC)

• Low relative humidity

• Irregular and unreliable rainfall

• Highest percentage of sunshine of any climate

• Large diurnal temperature range

• Highest daytime temperature of any climate

• Annual precipitation less than half the annual potential evapotranspiration

Question for Thought

• Deserts are often found along coast on the west side of continents in the midlatitudes. How can dry conditions exist along a coast?

Optional Links:

• The Desert biome