A desert is a dry region with very little rainfall. During the day, temperatures can rise above 50 Â°C (122 Â°F). However, nights in a desert can be extremely very cold. Most deserts are covered with sand and rocks. Animals and desert plants that live in this habitat are specially adapted to life with little water and extreme changes in temperature.
Some deserts, located at very high altitudes, are known as montane deserts. They are common in the Himalayas. Some, like the Tibetan Plateau, are comparatively flat. Very few animals can survive the extreme cold and dryness, but the yak lives in Tibet.
For most part deserts are dry and have no water bodies. However, small springs with trees and plants growing around them can be found in certain places. These isolated regions are called oases. An oasis is vital for all forms of life in the desert.
The Sahara is the worldâ€™s largest hot desert. It spreads right across northern Africa from the Atlantic Ocean in the west to the Red Sea in the east. Sand and rock cover most of the dry Sahara, but there are oases where people have lived for centuries.
Most deserts are hot during the day, but some deserts are in the coldest parts of the Earth. Some cold deserts are covered in ice throughout the year, allowing very few plants to grow. Cold deserts are also not very suitable for animals. Few species can survive such extreme cold for long periods of time. Antarctica is the largest cold desert in the world.
Patagonia in the southernmost part of South America and Gobi in Mongolia are also cold deserts.