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When does it first snow in Helena, MT?

At Helena, the typical date of the first measurable snowfall (0.1 inch or more in a day) is Nov 2. That is the median over the last 30 snow seasons: half of seasons saw it earlier, half later. In about 1 season in 10 it came by Oct 7, and in 1 in 10 not until Nov 16 or later. The earliest was Sep 29 (2019-20) and the latest Nov 23 (2021-22). A first snowfall of at least 1 inch in a single day typically arrives around Nov 5, and 100% of seasons had one. The first freeze of fall (a low of 32°F or colder) typically comes around Oct 1, and the last freeze of spring around May 13.

This season so far (2026-27, data through Oct 16, 2026): first measurable snow Oct 10; first freeze (32°F or colder) Oct 10 at this station. Compare with the typical dates above. This is observed data and can lag by a day or two, and it is not a forecast.

Nov 2Median first measurable snow (0.1"+)

Nov 5Median first 1"+ snowfall

38.3"Average snowfall per season

Oct 1Median first fall freeze (≤32°F)

May 13Median last spring freeze (≤32°F)

142Median freeze-free days between

First snowfall dates at Helena

First day with…	Median date	Typical range (10th–90th pct)	Earliest in 30 seasons	Latest in 30 seasons	Seasons with one
0.1" of snow or more (measurable)	Nov 2	Oct 7 – Nov 16	Sep 29 (2019-20)	Nov 23 (2021-22)	100%
1" of snow or more	Nov 5	Oct 11 – Dec 19	Sep 29 (2019-20)	Dec 30 (2018-19)	100%
3" of snow or more	Dec 14	Oct 23 – Jan 26	Sep 29 (2019-20)	Feb 21 (2013-14)	90%

Based on 21 seasons (July–June, 1995-96 to 2024-25) with at least 85% complete daily snowfall records at the station. Dates are for a single day’s snowfall, so "1 inch" means one calendar day with 1" or more, not total accumulation.

Chance the first snow has already happened by a given date

Snowfall	By Nov 1	By Dec 1	By Jan 1
0.1"+ (measurable)	48%	100%	100%
1"+	43%	86%	100%

In spring, the last measurable snowfall of the season typically falls around Apr 17 (median).

First and last freeze dates in Helena

Threshold	Event	Median date	Typical range (10th–90th pct)	Earliest / latest	Years with one
32°F or colder (freeze)	First in fall	Oct 1	Sep 17 – Oct 12	Sep 6 (1996) / Oct 24 (2023)	100%
32°F or colder (freeze)	Last in spring	May 13	May 1 – May 29	–	100%
28°F or colder (hard freeze)	First in fall	Oct 8	Sep 22 – Oct 27	Sep 12 (1999) / Oct 31 (2021)	100%
28°F or colder (hard freeze)	Last in spring	May 1	Apr 17 – May 13	–	100%

Based on the station’s daily minimum temperature, 1995–2024. “Freeze” here means a daily low at or below the threshold, which is not the same as visible frost. Your yard can differ by several degrees and days from an airport weather station, so use these as planning odds, not guarantees.

The median stretch between the last spring freeze and the first fall freeze (the freeze-free season) was about 142 days.

Nearby weather stations

Source station: Helena Ap Asos (USW00024144), elevation 3,865 ft. Data: NOAA NCEI GHCN-Daily. Computed by First Snow Dates; how we calculate this. Historical averages only; for a forecast see weather.gov.

Planning for winter? Heat pump vs gas furnace, propane and oil: heating cost in Montana (on our sister site PlugVsPump, from EIA prices).