Harman US

Helena, MT Weather & Growing Conditions

Today
48°F
Sunny
Sunny. High near 48, with temperatures falling to around 42 in the afternoon. Southwest wind around 2 mph.

7-day forecast

WhenTempForecastWindPrecip
Today 48°F Sunny 2 mph SW 0%
Tonight 26°F Mostly Clear 1 to 5 mph SW 0%
Thursday 48°F Partly Sunny 1 to 6 mph WSW 1%
Thursday Night 28°F Partly Cloudy 3 to 9 mph WSW 1%
Friday 51°F Mostly Sunny 3 to 7 mph SW 0%
Friday Night 34°F Mostly Cloudy 5 to 13 mph SSW 0%
Saturday 56°F Mostly Sunny 2 to 6 mph S 0%
Saturday Night 34°F Partly Cloudy 2 to 8 mph S 0%
Sunday 61°F Mostly Sunny 2 to 8 mph SSW 4%
Sunday Night 33°F Partly Cloudy 1 to 9 mph WSW 4%
Monday 53°F Partly Sunny 2 mph S 1%
Monday Night 33°F Mostly Cloudy 3 mph SSW 1%
Tuesday 57°F Mostly Sunny 2 to 6 mph SW 2%
Tuesday Night 35°F Partly Cloudy 6 mph SW 4%

Forecast source: National Weather Service (api.weather.gov). Updated through the day.

Growing snapshot for Helena, MT

Last spring frost
May 9
First fall frost
Sep 30
Growing season
142 days

Explore more for Helena, MT: full frost dates · planting calendar · Montana frost dates

Climate data from the nearest NOAA station, Helena Rgnl Ap, Mt (3.6 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.