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.
Today
65°F
Rain then Showers And Thunderstorms Likely
Rain before noon, then showers and thunderstorms likely between noon and 3pm, then a chance of rain. Cloudy. High near 65, with temperatures falling to around 62 in the afternoon. North wind around 8 mph. Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible.
7-day forecast for Helena Valley Northwest
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 65°F | Rain then Showers And Thunderstorms Likely | 8 mph N | 82% |
| Tonight | 43°F | Mostly Cloudy | 1 to 5 mph NNW | 11% |
| Sunday | 73°F | Mostly Sunny | 0 to 5 mph S | 0% |
| Sunday Night | 44°F | Mostly Clear | 3 mph SSW | 0% |
| Monday | 77°F | Sunny | 1 to 8 mph SSW | 0% |
| Monday Night | 46°F | Mostly Clear | 1 to 7 mph WSW | 0% |
| Tuesday | 78°F | Sunny | 0 to 5 mph S | 0% |
| Tuesday Night | 47°F | Mostly Clear | 1 to 5 mph SW | 1% |
| Wednesday | 79°F | Sunny | 0 to 8 mph SSE | 1% |
| Wednesday Night | 48°F | Mostly Clear | 2 to 6 mph SSW | 2% |
| Thursday | 79°F | Sunny | 2 to 7 mph SSE | 2% |
| Thursday Night | 48°F | Mostly Clear | 2 to 7 mph SSW | 5% |
| Friday | 77°F | Mostly Sunny | 2 to 8 mph S | 4% |
| Friday Night | 45°F | Slight Chance Light Rain then Partly Cloudy | 10 mph WNW | 18% |
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 Sep 19, 2026.