BUTTE - The National Weather Service says it's a historic arctic blast for the Mining City.
NWS Missoula staff say that on Sunday, March 3, the low sank to -26 at Bert Mooney Airport.
It's a record cold for March 3 - the previous record was -25 in 1976, and also the fifth coldest low for the month of March.
Monday, March 4 came in even colder, with the low in Butte recorded as -30. The previous day record was -25 on March 4, 1989.
Kalispell also saw a record low of -21 on Monday, beating a 1966 day record of -16.
NWS records date back to 1894.
(Story updated with new NOAA official records.)