The Lowest Temperature Extremes
The lowest temperature on record in the United States, –79.8°F, was observed at Prospect Creek Camp in the Endicott Mountains of northern Alaska (latitude 66°48'N, longitude 150°40'W) on Jan. 23, 1971. The lowest ever recorded in the conterminous 48 states, –69.7°F, occurred at Rogers Pass, in Lewis and Clark County, Mont., on Jan. 20, 1954. Rogers Pass is in mountainous and heavily forested terrain about one half of a mile east of and 140 ft below the summit of the Continental Divide.
The lowest annual normal (1941–1970 mean) temperature in the United States is 9.3°F for Barrow, Alaska, which lies on the Arctic coast. Barrow also has the coolest summers (June–August) with a normal temperature of 36.4°F. The lowest winter (December–February) normal temperature, is –15.7°F for Barter Island on the Arctic coast of northeast Alaska.
In the 48 conterminous states, Mt. Washington, N.H. (elevation 6,262 ft), has the lowest annual normal temperature, 26.9°F, and the lowest normal summer temperature, 46.8°F. A few stations in the northeast United States and in the upper Rocky Mountains have normal annual temperatures in the 30s; summer normal temperatures at these stations are in the low 50s. Winter normal temperatures are lowest in northeast North Dakota, 5.6°F for Langdon Experiment Farm, and in northwest Minnesota, 5.3°F for Hallock.