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
25°F
Partly Cloudy
Partly cloudy. Low around 25, with temperatures rising to around 29 overnight. West wind around 1 mph.
7-day forecast for Helena
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 25°F | Partly Cloudy | 1 mph W | 0% |
| Wednesday | 48°F | Mostly Sunny | 2 mph NW | 0% |
| Wednesday Night | 25°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 8 mph SW | 1% |
| Friday | 51°F | Mostly Sunny | 3 to 7 mph SW | 0% |
| Friday Night | 33°F | Mostly Cloudy | 3 to 12 mph SSW | 0% |
| Saturday | 56°F | Mostly Sunny | 2 to 6 mph SSE | 0% |
| Saturday Night | 33°F | Partly Cloudy | 2 to 8 mph S | 0% |
| Sunday | 61°F | Mostly Sunny | 2 to 7 mph SSW | 4% |
| Sunday Night | 33°F | Partly Cloudy | 0 to 8 mph SW | 4% |
| Monday | 53°F | Partly Sunny | 2 mph SSE | 1% |
| Monday Night | 32°F | Mostly Cloudy | 3 mph SSW | 1% |
| Tuesday | 57°F | Mostly Sunny | 1 to 5 mph SW | 2% |
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 Nov 4, 2026.