FrostDateByZip

Frost dates for 59417Browning, MT

The average last spring frost in Browning is June 8 and the average first fall frost is September 5, giving a typical growing season of about 88 days. Dates are based on NOAA 1991-2020 climate normals.

Average last spring frost
Jun 8

Safer after Jul 1 (1-in-10 risk)

Average first fall frost
Sep 5

Possible by Aug 20 (1-in-10 risk)

Growing season
88 days

Last frost typically in 224 days

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.
TemperatureLast spring: 90% / 50% / 10% chanceFirst fall: 10% / 50% / 90% chanceGrowing season (50%)Years with at least one
Light frost (36°F)——52 days100%
Frost / freeze (32°F)May 24 · Jun 8 · Jul 1Aug 20 · Sep 5 · Sep 2088 days100%
Hard freeze (28°F)May 7 · May 21 · Jun 7Sep 4 · Sep 23 · Oct 5122 days100%

Where these dates come from

ZIP code 59417 is matched to the NOAA station E Glacier, MT, 19.7 km away, at 4,806 ft elevation (436 ft higher than the ZIP code's center). Nearby stations for comparison:

StationElevationAvg last frostAvg first frost
E Glacier, MT (used)4,806 ftJun 8Sep 5
St Mary, MT4,560 ftJun 12Sep 5
St. Mary 1 Ssw, MT4,555 ftJun 3Sep 8
Cut Bank Muni Ap, MT3,838 ftMay 24Sep 15

Frost dates near Browning

Frequently asked questions

When is the last frost in Browning, MT?
For ZIP code 59417, the average last spring frost (32°F) is June 8, based on NOAA 1991-2020 climate normals for the E Glacier, MT weather station. There is a 1-in-10 chance of a frost after July 1.
When is the first frost in Browning, MT?
The average first fall frost (32°F) is September 5. There is a 1-in-10 chance of frost by August 20, so tender plants are at risk from that point on.
How long is the growing season in 59417?
In half of years, the frost-free season (between the last and first 32°F frost) is at least 88 days long.
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.