Helena, MT Weather & Growing Conditions
Overnight
45°F
Mostly Clear
Mostly clear, with a low around 45. Wind around 0 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 45°F | Mostly Clear | 0 mph | 0% |
| Tuesday | 78°F | Patchy Smoke | 0 to 6 mph NNE | 0% |
| Tuesday Night | 51°F | Mostly Clear | 5 mph W | 1% |
| Wednesday | 87°F | Sunny | 5 mph NW | 0% |
| Wednesday Night | 54°F | Mostly Clear | 6 mph W | 0% |
| Thursday | 94°F | Sunny | 1 to 9 mph W | 0% |
| Thursday Night | 58°F | Mostly Clear | 5 to 9 mph W | 0% |
| Friday | 99°F | Sunny | 1 to 15 mph WSW | 1% |
| Friday Night | 61°F | Mostly Clear | 9 to 14 mph W | 0% |
| Saturday | 95°F | Sunny | 1 to 12 mph W | 0% |
| Saturday Night | 61°F | Mostly Clear | 6 to 9 mph WNW | 0% |
| Sunday | 92°F | Sunny | 2 to 8 mph NW | 1% |
| Sunday Night | 59°F | Mostly Clear | 5 to 9 mph NW | 1% |
| Monday | 90°F | Sunny | 2 to 8 mph N | 1% |
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
Hardiness zone
5a
Explore more for Helena, MT: full frost dates · planting calendar · Montana frost dates
Climate data from the nearest NOAA station, Helena Rgnl Ap, Mt (3.8 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.