Frost dates in Jefferson County, Montana
The average last spring frost in Jefferson County falls May 9 to Jun 18 and the average first fall frost Sep 5 to Sep 27, depending on the ZIP code (50% odds, 32°F, NOAA 1991–2020 normals). USDA hardiness zone 4b to 5a. Places: Basin, Butte-Silver Bow (balance), Cardwell, Clancy, Elkhorn, Jefferson City. Pick a ZIP for 10% and 90% odds, soil temperature and the 7-day freeze forecast.
| ZIP | Place | Last spring frost | First fall frost | Zone |
|---|---|---|---|---|
| 59631 | Basin | Jun 7 | Sep 8 | 5a |
| 59632 | Elkhorn | Jun 7 | Sep 8 | 5a |
| 59634 | Clancy | Jun 18 | Sep 5 | 4b |
| 59638 | Jefferson City | Jun 18 | Sep 5 | 4b |
| 59721 | Cardwell | May 9 | Sep 27 | 5a |
| 59759 | Butte-Silver Bow (balance) | Jun 13 | Sep 5 | 5a |
Nearby counties
Broadwater County Silver Bow County Lewis and Clark County Deer Lodge County Powell County Madison County
All Montana counties · Download Montana frost dates (CSV)
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