Antarctica is technically classified as the largest desert on earth because it receives an average of only two inches of precipitation annually in its interior regions.

How a continent of ice can be a desert

A desert is defined by how little precipitation reaches the ground, not by how hot or sandy the landscape is. In Antarctica’s high interior, the air is extremely cold and holds little water vapor. Moisture-bearing weather systems also lose much of their water as they move inland from the ocean, leaving the central plateau exceptionally dry.

That dryness is easy to miss because the surface is buried under snow. But the ice sheet is the result of snow accumulating over vast stretches of time: even a small annual deposit can build up when it persists for thousands of years. A thick ice cover records long-term accumulation, not abundant yearly snowfall.

The coast and the interior tell different stories

Antarctica is not uniformly dry. Coastal areas receive more precipitation than the interior, and some get enough snowfall to support glaciers that flow toward the sea. Farther inland, snowfall is scarce, and winds can sweep loose snow away, exposing hard-packed ice or bare rock in some places.

This contrast matters when thinking about the continent’s landscape. The immense ice sheet does not mean every part of Antarctica gets frequent snow; it reflects slow accumulation across an enormous area and an immense span of time. In the coldest, driest interior, a year’s snowfall may amount to only a thin new layer—even though the ground beneath it holds ice built up over ages.