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
30°F
Mostly Clear
Mostly clear, with a low around 30. East wind 1 to 5 mph.
7-day forecast for St. Marie
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 30°F | Mostly Clear | 1 to 5 mph E | 0% |
| Wednesday | 49°F | Mostly Sunny | 0 to 5 mph NW | 0% |
| Wednesday Night | 29°F | Mostly Cloudy | 5 mph E | 0% |
| Thursday | 48°F | Mostly Sunny | 3 to 9 mph S | 0% |
| Thursday Night | 32°F | Partly Cloudy | 6 mph WSW | 0% |
| Friday | 50°F | Sunny | 5 to 12 mph WSW | 4% |
| Friday Night | 34°F | Partly Cloudy | 9 mph WSW | 5% |
| Saturday | 53°F | Sunny | 6 to 15 mph W | 2% |
| Saturday Night | 32°F | Mostly Clear | 6 mph S | 0% |
| Sunday | 58°F | Mostly Sunny | 8 mph SSW | 0% |
| Sunday Night | 36°F | Partly Cloudy | 8 to 15 mph W | 0% |
| Monday | 51°F | Mostly Sunny | 5 to 10 mph W | 1% |
| Monday Night | 33°F | Partly Cloudy | 5 mph SSW | 0% |
| Tuesday | 54°F | Mostly Sunny | 5 to 10 mph SSE | 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.