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).
Operation Deep Freeze
The operation involved the following ships:
On 31 October 1956, US Navy Rear Admiral George J. Dufek and others successfully landed an R4D Skytrain (Douglas DC-3) aircraft at the South Pole, as part of the expeditions mounted for the IGY. This was the first aircraft to land at the South Pole and the first time that Americans had set foot on the South Pole. The aircraft was named "Que Sera, Sera" after a popular song and is now on display at the Naval Aviation Museum in Pensacola, Florida. This marked the beginning of the establishment of the first permanent base, by airlift, at the South Pole (today known as the Amundsen–Scott South Pole Station) to support the International Geophysical Year. It was commissioned on January 1, 1957. The original station ("Old Byrd") lasted about four years before it began to collapse under the snow. Construction of a second underground station in a nearby location began in 1960, and it was used until 1972. The station was then converted into a summer-only field camp until it was abandoned in 2004-05. The mission's 2nd base, The Byrd Station a (former) research station established by the United States during the International Geophysical Year by the U.S. Navy during Operation Deep Freeze II in West Antarctica. The United States Antarctic Program airfield, built to service Operation Deep Freeze (first mission) was later named Williams Field or Willy Field.