When is the last frost in Bozeman, MT?

Frost is possible in any month at the nearest NOAA station (Big Sky 2Wnw, MT), so there is no reliable average last frost date.

When is the first frost in Bozeman, 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 59719Bozeman, MT

Frost is possible in any month near Bozeman, based on NOAA 1991-2020 records for the Big Sky 2Wnw, 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)	—	—	26 days	100%
Frost / freeze (32°F)	—	—	50 days	100%
Hard freeze (28°F)	May 26 · Jun 11 · Jun 28	Aug 23 · Sep 8 · Sep 23	87 days	100%

Where these dates come from

ZIP code 59719 is matched to the NOAA station Big Sky 2Wnw, MT, 51.1 km away, at 6,590 ft elevation (346 ft higher than the ZIP code's center). Nearby stations for comparison:

Station	Elevation	Avg last frost	Avg first frost
Big Sky 2Wnw, MT (used)	6,590 ft	—	—
Bozeman Montana State Univ, MT	4,913 ft	May 26	Sep 22
Bozeman 6 W Exp Farm, MT	4,775 ft	May 23	Sep 23
Bozeman Gallatin Fld, MT	4,427 ft	May 26	Sep 16

Frost dates near Bozeman

Bozeman, MT 59717 · last —, first —
Belgrade, MT 59714 · last May 26, first Sep 16
Livingston, MT 59047 · last May 27, first Sep 14
Clyde Park, MT 59018 · last May 27, first Sep 14
Pray, MT 59065 · last May 19, first Sep 25
Manhattan, MT 59741 · last May 26, first Sep 16
Emigrant, MT 59027 · last May 21, first Sep 27
Gallatin Gateway, MT 59730 · last —, first —

Frequently asked questions

When is the last frost in Bozeman, MT?: Frost is possible in any month at the nearest NOAA station (Big Sky 2Wnw, MT), so there is no reliable average last frost date.
When is the first frost in Bozeman, 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.