The lowest temperature ever recorded in the U.S. was -80 degrees in Prospect Creek, Alaska, north of Fairbanks, on Jan. 23, 1971. In the Lower 48, Montana holds the record for the all-time coldest temperature at negative 70 degrees, set at Rogers Pass – on the Continental Divide at 5,610 feet above sea level – on Jan. 20, 1954.

Source: Fox Weather