Vostok Station sits on the East Antarctic ice sheet about 3,500 meters (11,500 feet) above sea level, near the southern Pole of Cold. The reading came in the depths of the polar winter, in calm, clear conditions that let heat radiate into space. It remains the world's lowest officially recognised air temperature measured at a weather station. Satellites have since detected even colder surface temperatures elsewhere on the high Antarctic plateau.
The Soviet Union founded Vostok in December 1957, during the International Geophysical Year, and chose a site near the geomagnetic South Pole. It is one of the most isolated places on Earth: supplies arrive by tractor convoy across hundreds of miles of ice, and the air at that altitude holds less oxygen, so newcomers often suffer altitude sickness.
The record reading came at 05:45 Moscow time on July 21, 1983. At such temperatures, diesel fuel thickens and has to be treated, metal becomes brittle, and breathing the air unprotected can damage the lungs.
The station has also been the site of important science. Ice cores drilled there, reaching back more than 400,000 years, provided a detailed record of past climate and of carbon dioxide in the atmosphere. Beneath the station, under nearly four kilometers of ice, lies Lake Vostok, one of the largest subglacial lakes, which Russian drillers reached in 2012.