Helena, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Helena, a city in Lewis And Clark County, Montana.
Overnight
44°F
Mostly Clear
Mostly clear, with a low around 44. West wind around 1 mph.
7-day forecast for Helena
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 44°F | Mostly Clear | 1 mph W | 0% |
| Tuesday | 78°F | Patchy Smoke | 0 to 5 mph NNE | 0% |
| Tuesday Night | 48°F | Mostly Clear | 5 mph WNW | 1% |
| Wednesday | 86°F | Sunny | 1 to 5 mph WNW | 0% |
| Wednesday Night | 51°F | Mostly Clear | 6 mph W | 0% |
| Thursday | 94°F | Sunny | 1 to 9 mph WSW | 0% |
| Thursday Night | 54°F | Mostly Clear | 3 to 9 mph W | 0% |
| Friday | 98°F | Sunny | 0 to 16 mph WNW | 1% |
| Friday Night | 57°F | Mostly Clear | 7 to 15 mph W | 0% |
| Saturday | 95°F | Sunny | 1 to 12 mph W | 0% |
| Saturday Night | 57°F | Mostly Clear | 5 to 10 mph WNW | 0% |
| Sunday | 91°F | Sunny | 1 to 8 mph NW | 1% |
| Sunday Night | 56°F | Mostly Clear | 5 to 9 mph NW | 1% |
| Monday | 89°F | Sunny | 1 to 8 mph NNW | 1% |
Forecast source: National Weather Service (api.weather.gov) for Helena (46.595, -112.019). Updated through the day.
Growing snapshot for Helena
Last spring frost
May 9
First fall frost
Sep 30
Growing season
142 days
More local growing data for Helena: nearby ZIP 59625 weather · frost dates · planting calendar · Montana frost dates
Nearby towns & communities
Canyon Creek
Craig
East Helena
Helena Valley Northeast
Helena Valley Northwest
Helena Valley Southeast
Helena Valley West Central
Helena West Side
Lincoln
Marysville
Milford Colony
Montana City
Rimini
South Hills
Spokane Creek
Unionville
Wolf Creek
York
Climate data from the nearest NOAA station, Helena Rgnl Ap, Mt (3.6 mi from Helena). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.