Deserts are areas where the rainfall is too low to sustain any vegetation at all, or only very scanty scrub
Precipitation is usually scarce in a desert
Less than 25 cm/year
The hot deserts are situated in the subtropical climate zone where there is unbroken sunshine for the whole year due to the stable descending air and high pressure.
Examples include the Sahara, Saudi Arabia, large parts of Iran and Iraq, northwest India, California, South Africa and much of Australia.
Summer temperatures often reach 100 degrees Fahrenheit or higher.  At night, temperatures drop to 45 degrees Fahrenheit or lower
Many deserts have mild winters, while others have freezing temperatures and snow
The Gobi desert in Mongolia is an example of a cool desert. Though hot in summer, it shares the very cold winters of central Asia.
Climate affects animal life dramatically -- It makes less habitat for most of the animals, and affects the small range of animals living in the desert