Antarctica is largest desert post

A social media post shared on May 22, 2026 said Antarctica is the world’s largest desert because of how little precipitation it receives, not because it is cold. That claim matches standard reference definitions used by major science and education sources. Britannica, NASA and National Geographic all describe Antarctica as a desert on the basis of its dryness, even though the continent is covered in ice and is the coldest place on Earth. The key distinction is that climatology definitions of deserts focus on limited precipitation, not high temperature alone. ### Why can an ice-covered continent be called a desert? Britannica says Antarctica can be classified as a desert because it receives very little precipitation, with the inland polar plateau averaging about 2 inches, or 50 millimeters, a year in liquid-water equivalent. NASA similarly says Antarctica is considered a desert because it receives very little rain or snowfall. National Geographic says deserts get less than 25 centimeters, or 10 inches, of rainfall a year, and identifies Antarctica as the largest desert in the world. (britannica.com) That places Antarctica within the standard low-precipitation threshold commonly used in educational and reference material. ### Is temperature part of the definition at all? USGS says there are many desert definitions and classification systems, and that some rely on combinations of rainfall, temperature, humidity and other factors. (britannica.com) But it also says one long-used system divided deserts by the amount of precipitation they receive, and Britannica says a common textbook standard is less than 250 millimeters of precipitation a year. Britannica’s broader entry on deserts says their most fundamental characteristic is a shortage of available moisture. (education.nationalgeographic.org) That is why a place can be extremely cold and still qualify as a desert if it is dry enough. ### How dry is Antarctica, exactly? Britannica puts the inland Antarctic plateau at about 50 millimeters of precipitation a year, while the British Antarctic Survey says Antarctic snowfall is equivalent to about 150 millimeters of annual rain. (pubs.usgs.gov) Both figures are below the 250-millimeter threshold often used to define deserts. The difference reflects that precipitation varies across the continent, with interior areas much drier than some coastal zones. (britannica.com) The British Antarctic Survey also notes that Britain gets about 1,050 millimeters of annual rainfall, offering a direct comparison that underscores how arid Antarctica is despite its ice cover. ### So why do people associate deserts only with heat and sand? National Geographic says only about 10% of the world’s deserts are covered by dunes, and that deserts include landscapes such as rock, salt flats and even ice sheets. (britannica.com) It divides deserts into several types, including polar deserts. That is why Antarctica often surprises people in these discussions: its appearance fits a common image of ice and snow, while the scientific classification turns on aridity. (bas.ac.uk) NASA’s Antarctica FAQ and Britannica’s explainer both make that same point in plain terms. ### What should readers check if they want the source material? NASA’s current Antarctica FAQ, Britannica’s explainer on why Antarctica is a desert, USGS material on desert definitions, and National Geographic’s desert reference pages all set out the same basic framework: low precipitation is the central test. (education.nationalgeographic.org) Those pages remain the clearest starting points for readers who want to compare the social post against standard reference material. (nasa.gov)