When is the last frost in Clinton, MT?

Frost is possible in any month at the nearest NOAA station (Potomac, MT), so there is no reliable average last frost date.

When is the first frost in Clinton, MT?

Frost is possible in any month at the nearest NOAA station.

Are these frost dates a forecast?

No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.

Frost dates for 59825Clinton, MT

Frost is possible in any month near Clinton, based on NOAA 1991-2020 records for the Potomac, MT station.

Frost is possible in any month. Even summer nights can drop to freezing at this station, so protect tender plants whenever cold nights are forecast.

Frost risk by date

NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.

Spring dates: chance of a frost AFTER the date. Fall dates: chance of a frost BEFORE the date.
Temperature	Last spring: 90% / 50% / 10% chance	First fall: 10% / 50% / 90% chance	Growing season (50%)	Years with at least one
Light frost (36°F)	—	—	20 days	100%
Frost / freeze (32°F)	—	—	45 days	100%
Hard freeze (28°F)	May 20 · Jun 2 · Jun 27	Aug 18 · Sep 4 · Sep 21	91 days	100%

Where these dates come from

ZIP code 59825 is matched to the NOAA station Potomac, MT, 16.2 km away, at 3,690 ft elevation (104 ft higher than the ZIP code's center). Nearby stations for comparison:

Station	Elevation	Avg last frost	Avg first frost
Potomac, MT (used)	3,690 ft	—	—
Missoula 2 Ne, MT	3,420 ft	May 10	Oct 1
Missoula Intl Ap, MT	3,192 ft	May 16	Sep 26
Missoula 6 Nw Wfo, MT	3,197 ft	May 6	Oct 4

Frost dates near Clinton

Bonner, MT 59823 · last May 10, first Oct 1
Milltown, MT 59851 · last May 10, first Oct 1
Missoula, MT 59806 · last May 6, first Oct 4
Lolo, MT 59847 · last May 16, first Sep 26
Florence, MT 59833 · last May 22, first Sep 19
Drummond, MT 59832 · last —, first —
Stevensville, MT 59870 · last May 22, first Sep 19
Hall, MT 59837 · last —, first —

Frequently asked questions

When is the last frost in Clinton, MT?: Frost is possible in any month at the nearest NOAA station (Potomac, MT), so there is no reliable average last frost date.
When is the first frost in Clinton, MT?: Frost is possible in any month at the nearest NOAA station.
Are these frost dates a forecast?: No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.