Which Is the Driest Continent?

Although it holds about 70% of the world fresh water (locked in ice), Antarctica is technically the driest continent. The interior receives an average of only about 50 mm of precipitation per year (water equivalent), and the continent as a whole averages about 166 mm — less than the Sahara Desert. The extreme cold means the air holds very little moisture. The Dry Valleys of McMurdo, one of the most extreme deserts on Earth, have not seen rain for roughly 2 million years. Some ice-free areas are so dry that any fallen snow sublimates (turns directly to vapour) before it can accumulate.