|Location of Lake Vostok in Antarctica. Original a composite satellite photo by NASA (public domain via Wikipedia)|
This was recorded at the Vostok Station in the Antarctic on July 21, 1983 when it was winter in the southern hemisphere. According to NOAA's National Climate Data Center, this is the most reliably documented occurrence of the lowest temperature in the world. Kind of refreshing to think about during the current summer heat wave in the northern hemisphere!