What is the driest continent on Earth?

The driest continent on Earth is Antarctica. Although it is covered by an enormous ice sheet, Antarctica is officially a polar desert because it receives very little precipitation.

Antarctica averages about 150 millimetres of water-equivalent precipitation each year, most of it snow. The continental interior is far drier, often receiving less than 50 millimetres annually. Strong katabatic winds can remove snow through blowing and sublimation, leaving some areas nearly barren.

Its dryness can be surprising because Antarctica contains roughly 70% of Earth’s freshwater, locked in ice. That ice does not make the climate humid: the continent’s extreme cold means the atmosphere holds little water vapour. The McMurdo Dry Valleys are among the clearest examples of its desert conditions.

Antarctica is also Earth’s coldest and windiest continent. At Vostok Station, scientists recorded −89.2°C on 21 July 1983, the lowest official surface air temperature ever measured. The Arctic is not the same kind of continent-scale desert because its surrounding ocean moderates the climate.