![]() ![]() Rainfall is rare and mainly occurs during the summer in coastal areas and surrounding islands. Almost all Antarctic precipitation falls as snow. Areas that receive less than 250 millimetres (9.8 inches) of precipitation per year are classified as deserts. The actual rates vary widely, from high values over the Peninsula (15 to 25 inches a year) to very low values (as little as 50 millimetres (2.0 inches) in the high interior (Bromwich, Reviews of Geophysics, 1988). The total precipitation on Antarctica, averaged over the entire continent, is about 166 millimetres (6.5 inches) per year (Vaughan et al., J. Map of average annual precipitation on Antarctica (mm liquid equivalent) Higher temperatures occur in January along the coast and average slightly below freezing. The Antarctic Peninsula has the most moderate climate. East Antarctica is colder than West Antarctica because of its higher elevation. Severe low temperatures vary with latitude, elevation, and distance from the ocean. Along the Antarctic Peninsula, temperatures as high as 18.3 ☌ (64.9 ☏) have been recorded, though the summer temperature is below 0 ☌ (32 ☏) most of the time. Īt the South Pole, the highest temperature ever recorded was −12.3 ☌ (9.9 ☏) on 25 December 2011. Monthly means at McMurdo Station range from −26 ☌ (−14.8 ☏) in August to −3 ☌ (26.6 ☏) in January. The coast is warmer on the coast Antarctic average temperatures are around −10 ☌ (14.0 ☏) (in the warmest parts of Antarctica) and in the elevated inland they average about −55 ☌ (−67.0 ☏) in Vostok. The mean annual temperature of the interior is −57 ☌ (−70.6 ☏). This temperature is not directly comparable to the –89.2 ☌ reading quoted above, since it is a skin temperature deduced from satellite-measured upwelling radiance, rather than a thermometer-measured temperature of the air 1.5 m (5 ft) above the ground surface. It was discovered during a National Snow and Ice Data Center review of stored data in December 2013 but revised by researchers on 25 June 2018. This unnamed part of the Antarctic plateau, between Dome A and Dome F, was measured on 10 August 2010, and the temperature was deduced from radiance measured by the Landsat 8 and other satellites. Satellite measurements have identified even lower ground temperatures, with −93.2 ☌ (−135.8 ☏) having been observed at the cloud-free East Antarctic Plateau on 10 August 2010. The elevation of the location is 3,488 meters (11,444 feet). For comparison, this is 10.7 ☌ (19.3 ☏) colder than subliming dry ice (at sea level pressure). The lowest air temperature record, the lowest reliably measured temperature on Antarctica was set on 21 July 1983, when a temperature of −89.2 ☌ (−128.6 ☏) was observed at Vostok Station. The Antarctic temperature changes during the last several glacial and interglacial cycles of the present ice age ![]()
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