What is the coldest temperature ever recorded on the Earth's surface (mountain peak or sea level)?

During the southern hemisphere winter on 21 July 1983, temperatures at Russia's Vostok research station in Antarctica plunged to -89.2°C (-128.6°F), which is 54 degrees colder than the winter average there. This is the coldest temperature ever recorded on Earth. The Vostok site in Antarctica was chosen by the Soviet Union for research with the aim of drilling deep into ancient ice. French and - later - American scientists began to participate in the deep-core activities at the site.