Missoula, MT Frost Dates
The last spring frost in Missoula usually comes around May 16 and the first fall frost around September 26.
| Spring (last) | Fall (first) | |
|---|---|---|
| Frost, 32°F | May 16 | September 26 |
| Hard freeze, 28°F | May 2 | October 6 |
Growing season: about 130 days.
Frequently asked questions
When is the last frost in Missoula, MT?
The median date of the last spring frost (32°F) is May 16. In half of years the last frost comes earlier and in half it comes later, so waiting a week or two past May 16 lowers the risk for tender plants.
When is the first frost in Missoula?
The median date of the first fall frost (32°F) is September 26, and a hard freeze (28°F) usually follows around October 6.
How long is the growing season in Missoula?
About 130 days between the median last spring frost and first fall frost.
NOAA NCEI U.S. Climate Normals 1991-2020, station USW00024153. Median (50% probability) dates. Low spots and valleys can frost later in spring and earlier in fall than the station.