South Pole
In midsummer, as the sun reaches its maximum elevation of about 23.5 degrees, high temperatures at the South Pole in January average at . As the six-month "day" wears on and the sun gets lower, temperatures drop as well: they reach around sunset (late March) and sunrise (late September). In midwinter, the average temperature remains steady at around . The highest temperature ever recorded at the Amundsen–Scott South Pole Station was on Christmas Day, 2011, and the lowest was on June 23, 1982 (for comparison, the lowest temperature directly recorded anywhere on earth was at Vostok Station on July 21, 1983, though was measured indirectly by satellite in East Antarctica between Dome A and Dome F in August 2010). Mean annual temperature at the South Pole is -49.3 °C (-56.7 °F).
North Pole
While the South Pole lies on a continental land mass, the North Pole is located in the middle of the Arctic Ocean amid waters that are almost permanently covered with constantly shifting sea ice. This makes it impractical to construct a permanent station at the North Pole (unlike the South Pole). However, the Soviet Union, and later Russia, constructed a number of manned drifting stations on a generally annual basis since 1937, some of which have passed over or very close to the Pole. Since 2002, the Russians have also annually established a base, Barneo, close to the Pole. This operates for a few weeks during early spring. Studies in the 2000s predicted that the North Pole may become seasonally ice-free because of Arctic ice shrinkage, with timescales varying from 2016 to the late 21st century or later.