Antarctica is the largest desert on Earth, as classified by annual precipitation. Although its surface is covered by ice, most of the continent receives very little snowfall, making it a polar desert rather than a warm sandy desert.
Antarctica covers about 14 million square kilometres, and some parts of its interior receive less than 50 millimetres of precipitation annually. The ice sheet is enormous because snowfall accumulates over thousands of years and melts very slowly.
The Sahara is the world’s largest hot desert, but it is smaller than Antarctica. This distinction often causes confusion because everyday speech commonly links the word “desert” with heat and sand. In scientific geography, aridity and precipitation are more important than temperature or surface appearance.
Antarctica also contains the McMurdo Dry Valleys, one of Earth’s coldest and driest regions. Katabatic winds, extreme cold and limited moisture make the landscape unusually barren.