Your nature year
Helena, Montanathrough the year
When do frost, green-up and fall color come to Helena?
We follow 3 places within 150 miles of Helena; the nearest lies 122 miles to the west. Lost Horse Canyon, 122 miles from Helena, is the nearest fall foliage spot on this site, October (regional timing).
Red Rock Lakes Refuge (138 mi) is the pick for wildflowers, June and July (local timing). At the Helena Airport ASOS weather station (1.6 mi), the average first fall frost is Sep 30 and the last spring frost May 9, which leaves Helena some 144 growing days. Spring green-up reaches town around Apr 14, with first blooms around May 20.
Checked against 3 official sources · How we check →
Sources: US Census Bureau, 2024 Gazetteer (places) ↗ (opens in a new tab), US Census Bureau, city and town population estimates, 2024 ↗ (opens in a new tab), NOAA NCEI U.S. Climate Normals 1991–2020 (annual/seasonal) ↗ (opens in a new tab)
Near Helena right now
- Last spring frost usually around May 9 · first fall frost around Sep 30NOAA 1991–2020 normals, Helena Airport ASOS (1.6 mi, 50% dates)~7 months
- In season nearby: Fall foliage2 places in their usual window now, listed belowIn season
- Wildflowers · next season nearby · 138 miLocal timing: June and July~8 months
Places near Helena
Mountain wildflowers in MontanaWildlife refuge
138 mi
Best viewing: June and JulyU.S. Fish and Wildlife Service ↗
Helena's nature year
| Month | What to see | Where |
|---|---|---|
| April |
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| May |
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| June–July |
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| September |
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| October |
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Helena's year at a glance
- Frost possible
- Frost-free, ~May 9 to ~Sep 30
- First leaf ~Apr 14
- First bloom ~May 20
- Today
Frost and green-up
Last spring frost
May 9
Average (50% date)
First fall frost
Sep 30
About 144 days without frost between
Spring green-up
Apr 14
First bloom around May 20
Frost: NOAA 1991–2020 climate normals at Helena Airport ASOS (1.6 mi from Helena), the day a 32 °F night is as likely as not. Green-up: the USA-NPN Spring Index, 1991–2020 average at the town.
Snow in Helena
Snow usually becomes possible around Nov 5 (our calculation from NOAA's daily snow chances: the first day the chance of 0.1" or more of snow reaches 10%). NOAA's normals at Helena Airport ASOS (1.6 mi away): 37 inches of snow in an average year, about 12.5 days with 1 inch or more.
NOAA's chance of at least 0.1 inch of snow on each date (one value per week, September to May), averaged over 1991–2020. A typical year, not a forecast.
Questions people ask
When is the first frost in Helena?
On average around Sep 30, and the last spring frost around May 9: about 144 days without frost between. These are NOAA's 1991–2020 normals at Helena Airport ASOS, 1.6 miles away (the day a 32 °F night is as likely as not).
When does spring green-up reach Helena?
The USA-NPN Spring Index puts first leaf around Apr 14 and first bloom around May 20, on average for 1991–2020 at the town.
Where can I see fall foliage near Helena?
The nearest are Lost Horse Canyon (122 miles) and Lemhi Pass (137 miles). Lost Horse Canyon: regional timing: October. Lemhi Pass: local timing: by late September, and Agency Creek in October. Distances are straight-line.
Where can I see wildflowers near Helena?
The nearest is Red Rock Lakes Refuge (138 miles). Red Rock Lakes Refuge: local timing: June and July. Distances are straight-line.
When does it start snowing in Helena?
Snow usually becomes possible around Nov 5. That date is our calculation from NOAA's daily snow chances: the first day the chance of 0.1" or more of snow reaches 10%, at Helena Airport ASOS. An average year brings 37 inches (NOAA 1991–2020). A typical year, not a forecast.Sources: NOAA NCEI U.S. Climate Normals 1991–2020 (annual/seasonal snowfall) ↗ (opens in a new tab), NOAA NCEI U.S. Climate Normals 1991–2020 (daily snowfall probabilities) ↗ (opens in a new tab)
How we know
US Census Bureau, 2024 Gazetteer (places) (opens in a new tab) (Sep 27) · US Census Bureau, city and town population estimates, 2024 (opens in a new tab) (Sep 27) · NOAA NCEI U.S. Climate Normals 1991–2020 (annual/seasonal) (opens in a new tab) (Sep 27) · USA National Phenology Network, Spring Index 1991–2020 averages (opens in a new tab) (Sep 27)