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).
Martin A. Pomerantz
Pomerantz saw the potential of the South Pole as an observing platform remarkably early. Its proximity to the South magnetic pole of the Earth means that charged cosmic rays can be detected there without the deflections they experience when detected at lower latitudes. Astronomical observations near the Earth's poles can be done over long periods, without the diurnal variations at lower latitudes. The South Pole is at an altitude of nearly , so the astronomical seeing should be comparable to other high-altitude observatories; the extreme cold in Antarctica also corresponds to relatively little water vapor in the atmosphere there, which is a particular advantage for infrared astronomy. Finally, the South Pole lies at the top of a very deep, nearly permanent ice sheet that has been used to advantage in experiments such as the IceCube Neutrino Detector.