Frost dates · Montana
When is the first frost in Great Falls?
Great Falls right now
49°FClear skies
- Today56°F / 42°FClear skies
- Tomorrow57°F / 36°FClear skies
- Monday56°F / 38°FClouds
Make the most of it, obviously.
Live from OpenWeatherMap. Alerts from the National Weather Service.
In a typical year, Great Falls’s first frost comes around September 24 and its last around May 19.
One year in ten the first frost comes as early as September 9, and nine years in ten it has arrived by October 5. One year in ten the last frost is over as early as May 7, and nine years in ten it is over by June 2. Great Falls averages about 168 nights a year at 32°F or colder, with about 126 frost-free days in between in a typical year. It’s frost season here, and the last frost usually comes around May 19. That makes it the 3rd earliest first frost of the 117 cities we track where it freezes most years.
Last updated
No freeze in the forecast for the next 48 hours.
Great Falls gets its first frost in late September, before most of the country has even found its jacket.
Live 48-hour check from OpenWeatherMap, refreshed about every half hour. Alerts from the National Weather Service.
Frost dates, early, typical and late years
| Early year (1 in 10) | Typical | Late year (1 in 10) | |
|---|---|---|---|
| First frost | September 9 | September 24 | October 5 |
| Last frost | May 7 | May 19 | June 2 |
A frost date here is a night when the official thermometer reads 32°F or colder. Frost on the ground can show up on clear, calm nights a few degrees milder.
Cities with about the same first frost
- Casper, Wyoming: first frost around September 22
- Missoula, Montana: first frost around September 26
- Bismarck, North Dakota: first frost around September 27
Source: NOAA U.S. Climate Normals, 1991 to 2020, station USW00024143.