When is the last frost in Philipsburg, MT?

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

When is the first frost in Philipsburg, 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 59858Philipsburg, MT

Frost is possible in any month near Philipsburg, based on NOAA 1991-2020 records for the Phillipsburg Rs, 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)	—	—	31 days	100%
Frost / freeze (32°F)	—	—	65 days	100%
Hard freeze (28°F)	May 13 · May 29 · Jun 18	Aug 28 · Sep 12 · Sep 27	105 days	100%

Where these dates come from

ZIP code 59858 is matched to the NOAA station Phillipsburg Rs, MT, 1 km away, at 5,270 ft elevation (93 ft higher than the ZIP code's center). Nearby stations for comparison:

Station	Elevation	Avg last frost	Avg first frost
Phillipsburg Rs, MT (used)	5,270 ft	—	—
Anaconda, MT	5,230 ft	Jun 1	Sep 14
Drummond Aviation, MT	4,000 ft	—	—
Deer Lodge 3 W, MT	4,850 ft	—	—

Frost dates near Philipsburg

Hall, MT 59837 · last —, first —
Anaconda, MT 59711 · last Jun 1, first Sep 14
Drummond, MT 59832 · last —, first —
Gold Creek, MT 59733 · last —, first —
Warm Springs, MT 59756 · last —, first —
Deer Lodge, MT 59722 · last —, first —
Garrison, MT 59731 · last —, first —
Butte, MT 59750 · last Jun 13, first Sep 5

Frequently asked questions

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