Are Deserts Always Hot?

Deserts have come to symbolize for us places of extreme heat. The fact is, most of the famous desert of the world are places where the sun beats down without mercy. But this does not mean that a desert must be a place where it is always hot. Let us get a definition of a desert and we will see why this is so. A desert is a region where only special forms of life can exist because there is a shortage of moisture.

In a "hot" desert, there simply is not enough rainfall. So the definition holds true. But suppose there is a region where all water is frozen solid and cannot be used by plants. This satisfies the definition, too. Only it would make this a "cold" desert.

Did you know, for example, that much of the Arctic is really a desert? There is less than 40 centimeters of rainfall a year, and most of the water is frozen. So it is properly called a desert. The great Gobi Desert in the middle of Asia is bitterly cold in winter time. Most of the dry, hot deserts which we are familiar are found in two belts around the world, just north and south the Equator.

They are caused by high atmospheric pressures that exist in those areas and prevent rain from falling. Other deserts, which are found farther away from the Equator, Are the result of being in "the rain shadows". This is the name for an effect that is caused by mountain barriers that catch rainfall on their seaward side and leave the interior region dry.

No great rivers originate in deserts. But a river may rise in moister areas and across great deserts on its way to the sea. The Nile, for example, flows through the desert region of the Sahara and the Colorado River flows through a dessert, too.