When is the last frost in Marion, MT?

Frost is possible in any month at the nearest NOAA station (Libby 32 Sse, MT), so there is no reliable average last frost date.

When is the first frost in Marion, 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 59925Marion, MT

Frost is possible in any month near Marion, based on NOAA 1991-2020 records for the Libby 32 Sse, 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)	—	—	19 days	100%
Frost / freeze (32°F)	—	—	44 days	100%
Hard freeze (28°F)	—	—	93 days	100%

Where these dates come from

ZIP code 59925 is matched to the NOAA station Libby 32 Sse, MT, 37.6 km away, at 3,440 ft elevation (1,278 ft lower than the ZIP code's center). Nearby stations for comparison:

Station	Elevation	Avg last frost	Avg first frost
Libby 32 Sse, MT (used)	3,440 ft	—	—
Kalispell Glacier Ap, MT	2,957 ft	May 31	Sep 10
Whitefish, MT	3,100 ft	May 16	Sep 25
Creston, MT	2,935 ft	May 12	Sep 25

Frost dates near Marion

Kila, MT 59920 · last May 31, first Sep 10
Kalispell, MT 59903 · last May 16, first Sep 25
Proctor, MT 59929 · last May 1, first Oct 15
Somers, MT 59932 · last May 12, first Sep 25
Lakeside, MT 59922 · last May 12, first Sep 25
Lonepine, MT 59848 · last May 15, first Sep 28
Elmo, MT 59915 · last May 10, first Oct 5
Dayton, MT 59914 · last May 1, first Oct 15

Frequently asked questions

When is the last frost in Marion, MT?: Frost is possible in any month at the nearest NOAA station (Libby 32 Sse, MT), so there is no reliable average last frost date.
When is the first frost in Marion, 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.