When is the last frost in Babb, MT?

For ZIP code 59411, the average last spring frost (32°F) is June 12, based on NOAA 1991-2020 climate normals for the St Mary, MT weather station. There is a 1-in-10 chance of a frost after July 3.

When is the first frost in Babb, MT?

The average first fall frost (32°F) is September 5. There is a 1-in-10 chance of frost by August 18, so tender plants are at risk from that point on.

How long is the growing season in 59411?

In half of years, the frost-free season (between the last and first 32°F frost) is at least 82 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.

Frost dates for 59411Babb, MT

The average last spring frost in Babb is June 12 and the average first fall frost is September 5, giving a typical growing season of about 82 days. Dates are based on NOAA 1991-2020 climate normals.

Average last spring frost: Jun 12
Average first fall frost: Sep 5
Growing season: 82 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.
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)	—	—	50 days	100%
Frost / freeze (32°F)	May 27 · Jun 12 · Jul 3	Aug 18 · Sep 5 · Sep 21	82 days	100%
Hard freeze (28°F)	May 6 · May 19 · Jun 7	Sep 1 · Sep 20 · Oct 4	121 days	100%

Where these dates come from

ZIP code 59411 is matched to the NOAA station St Mary, MT, 16.2 km away, at 4,560 ft elevation (561 ft lower than the ZIP code's center). Nearby stations for comparison:

Station	Elevation	Avg last frost	Avg first frost
St Mary, MT (used)	4,560 ft	Jun 12	Sep 5
St. Mary 1 Ssw, MT	4,555 ft	Jun 3	Sep 8
Del Bonita, MT	4,337 ft	May 28	Sep 16
E Glacier, MT	4,806 ft	Jun 8	Sep 5

Frost dates near Babb

Browning, MT 59417 · last Jun 8, first Sep 5
East Glacier Park, MT 59434 · last Jun 8, first Sep 5
West Glacier, MT 59936 · last May 18, first Sep 20
Essex, MT 59916 · last May 9, first Oct 1
Coram, MT 59913 · last May 18, first Sep 20
Martin City, MT 59926 · last May 9, first Oct 1
Polebridge, MT 59928 · last —, first —
Hungry Horse, MT 59919 · last May 9, first Oct 1

Frequently asked questions

When is the last frost in Babb, MT?: For ZIP code 59411, the average last spring frost (32°F) is June 12, based on NOAA 1991-2020 climate normals for the St Mary, MT weather station. There is a 1-in-10 chance of a frost after July 3.
When is the first frost in Babb, MT?: The average first fall frost (32°F) is September 5. There is a 1-in-10 chance of frost by August 18, so tender plants are at risk from that point on.
How long is the growing season in 59411?: In half of years, the frost-free season (between the last and first 32°F frost) is at least 82 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.