St. Marie, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for St. Marie, a community in Valley County, Montana.
Tonight
31°F
Mostly Clear
Mostly clear, with a low around 31. Northeast wind around 2 mph.
7-day forecast for St. Marie
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 31°F | Mostly Clear | 2 mph NE | 0% |
| Wednesday | 49°F | Sunny | 0 to 5 mph NNW | 0% |
| Wednesday Night | 28°F | Partly Cloudy | 5 mph ENE | 0% |
| Thursday | 47°F | Partly Sunny | 3 to 9 mph SSE | 0% |
| Thursday Night | 32°F | Partly Cloudy | 6 mph WSW | 0% |
| Friday | 49°F | Sunny | 5 to 10 mph WSW | 0% |
| Friday Night | 34°F | Partly Cloudy | 6 to 9 mph SW | 0% |
| Saturday | 53°F | Sunny | 5 to 13 mph W | 0% |
| Saturday Night | 33°F | Partly Cloudy | 6 mph S | 0% |
| Sunday | 58°F | Mostly Sunny | 8 mph SSW | 0% |
| Sunday Night | 37°F | Partly Cloudy | 7 to 12 mph W | 0% |
| Monday | 52°F | Mostly Sunny | 5 to 10 mph WNW | 0% |
| Monday Night | 33°F | Partly Cloudy | 5 mph SSW | 1% |
| Tuesday | 54°F | Mostly Sunny | 5 to 8 mph S | 1% |
Forecast source: National Weather Service (api.weather.gov) for St. Marie (48.405, -106.499). Updated through the day.
Growing snapshot for St. Marie
Last spring frost
May 13
First fall frost
Sep 27
Growing season
134 days
Hardiness zone
4a
More local growing data for St. Marie: nearby ZIP 59231 weather · frost dates · planting calendar · Montana frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, St Marie, Mt (1.4 mi from St. Marie). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.