The Potomac, Montana station reported a low temp of -29°F Sunday morning. This is the lowest temperature measured at an official climate site anywhere in the U.S. so early in the season in any year. Previous lows by Oct 25: -20°F at Babb 6 NE, Blackleaf, and Bowen, MT, 10/24-25/1919.
At Townsend MT, the low of -5 not only set a daily record, but broke the old record by 16 degrees! Records at Townsend go back to 1901. Other low temps: -15 at Sula and -13 at Ronan. Melville had a low of -11 and a high temperature of just +4F.