First and last freeze dates in St. Marie, MT
The first freeze of fall (a low of 32°F or colder) typically comes around Sep 26, and the last freeze of spring around May 15.
Sep 26Median first fall freeze (≤32°F)
May 15Median last spring freeze (≤32°F)
134Median freeze-free days between
First and last freeze dates in St. Marie
| Threshold | Event | Median date | Typical range (10th–90th pct) | Earliest / latest | Years with one |
|---|---|---|---|---|---|
| 32°F or colder (freeze) | First in fall | Sep 26 | Sep 13 – Oct 7 | Sep 8 (2020) / Oct 13 (2024) | 100% |
| 32°F or colder (freeze) | Last in spring | May 15 | May 2 – May 22 | – | 100% |
| 28°F or colder (hard freeze) | First in fall | Oct 5 | Sep 23 – Oct 16 | Sep 8 (2020) / Oct 28 (2015) | 100% |
| 28°F or colder (hard freeze) | Last in spring | Apr 25 | Apr 17 – May 16 | – | 100% |
Based on the station’s daily minimum temperature, 1995–2024. “Freeze” here means a daily low at or below the threshold, which is not the same as visible frost. Your yard can differ by several degrees and days from an airport weather station, so use these as planning odds, not guarantees.
The median stretch between the last spring freeze and the first fall freeze (the freeze-free season) was about 134 days.
Nearby weather stations
Source station: St Marie (USW00094010), elevation 2,756 ft. Data: NOAA NCEI GHCN-Daily. Computed by First Snow Dates; how we calculate this. Historical averages only; for a forecast see weather.gov.
Planning for winter? Heat pump vs gas furnace, propane and oil: heating cost in Montana (on our sister site PlugVsPump, from EIA prices).