Endangered hot arid habitats
Threatened tropical semi-desert habitats
The principal tropical deserts are the Sahara and the Kalahari in Africa, the Sonoran in northern Mexico and the southwestern United States, those of Australia, and those of Arabia, Iran and Pakistan in southwestern Asia. The tropical desert, or arid tropical climate, generally lies between 15ø and 30ø latitude where atmospheric circulation brings dry, subtropical air into mid-latitudes. Mean monthly temperatures in the summer reach well above 35øC, with extremes of more than 55øC. Only short grasses and desert shrubs survive in the dry tropics.