Helena Valley Northwest, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Helena Valley Northwest, a community in Lewis And Clark County, Montana.
Overnight
43°F
Mostly Clear
Mostly clear, with a low around 43. Wind around 0 mph.
7-day forecast for Helena Valley Northwest
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 43°F | Mostly Clear | 0 mph | 0% |
| Tuesday | 78°F | Patchy Smoke | 0 to 6 mph ENE | 0% |
| Tuesday Night | 46°F | Mostly Clear | 2 to 6 mph NNW | 1% |
| Wednesday | 86°F | Sunny | 1 to 6 mph WSW | 0% |
| Wednesday Night | 50°F | Mostly Clear | 2 to 9 mph W | 0% |
| Thursday | 93°F | Sunny | 1 to 10 mph W | 0% |
| Thursday Night | 54°F | Mostly Clear | 3 to 13 mph W | 0% |
| Friday | 97°F | Sunny | 1 to 17 mph SW | 0% |
| Friday Night | 55°F | Mostly Clear | 6 to 20 mph W | 0% |
| Saturday | 94°F | Sunny | 1 to 13 mph WSW | 0% |
| Saturday Night | 55°F | Mostly Clear | 3 to 13 mph WNW | 0% |
| Sunday | 91°F | Sunny | 1 to 8 mph NW | 0% |
| Sunday Night | 54°F | Mostly Clear | 5 to 10 mph NW | 1% |
| Monday | 89°F | Sunny | 1 to 7 mph N | 1% |
Forecast source: National Weather Service (api.weather.gov) for Helena Valley Northwest (46.729, -112.058). Updated through the day.
Growing snapshot for Helena Valley Northwest
Last spring frost
May 9
First fall frost
Sep 30
Growing season
142 days
Hardiness zone
4b
More local growing data for Helena Valley Northwest: nearby ZIP 59636 weather · frost dates · planting calendar · Montana frost dates
Nearby towns & communities
Canyon Creek
Craig
East Helena
Helena
Helena Valley Northeast
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 (7.2 mi from Helena Valley Northwest). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.