Hot deserts are dispersed throughout the world on four of the seven continents. Hot deserts are classified as subtropical biomes meaning the climate and weather does not fluctuate to include cold temperatures and variations in weather. This creates an environment in which certain ecosystems of plants and animals flourish.
Hot and dry deserts are classified according to the annual amount of rainfall. A hot desert receives less than 25 cm of rain per year. The precipitation of hot deserts differs from cold deserts in that cold deserts receive snow.
The Tropic of Cancer and Tropic of Capricorn lines of latitude are consistent with the location of hot and dry deserts around the world because of the proximity to the equator, which absorbs intense amounts of sun, warming the land and ocean currents around it.
Hot deserts lack humidity and this allows the sun's rays to penetrate the atmosphere. Hot desert temperatures are warm year-round, fluctuating between 18C and 25C. Temperatures escalate during the summer months in the range of 40C to 48C.
Vegetation is scarce in hot deserts because of the extreme temperatures and lack of rainfall. Shrubs and short trees, such as the saguaro cactus and prickly pear bush, adapt to the climate by storing water.
Hot desert species include an array of reptiles and insects, such as snakes, lizards, tarantulas and locusts. Owls, kangaroos, coyotes, jackals and pumas also live in hot deserts.
Hot desert animals use behavioural and physical adaptations to survive the extreme conditions. Behavioural adaptations include nocturnal activity, meaning some animals burrow during the day when the sun is hottest and hunt at night when temperatures decrease. Physical adaptations include body parts that allow animals to acquire and store water by tapping succulent plants.
Hot deserts of the world include the Chihuahuan, Mojave and Sonoran, located in North America; the Monte in Argentina; the Sahara and Kalahari of Africa; the Thar of Pakistan and India; the Arabian desert, located on the Arabian peninsula; and Australia's Great Sandy, Victoria, Simpson, Gibson and Sturt deserts.
The Sahara in Africa is the largest desert in the world, covering 3,500,000 square miles. The Chihuahuan desert is the largest in North America, extending from north central Mexico to the south-western region of the United States and covering 175,000 square miles.
The topography of hot deserts includes sand, sand dunes, gravel, stone, plateaus, mountains, mesas, salt flats and rocky regions.
People have and continue to live in hot deserts. Desert dwellers include the Aborigines in Australia, the African Bushman of the Kalahari, the inhabitants of the Mojave Desert, and the Bedouin people of the Sahara.