St. Marie, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for St. Marie, a community in Valley County, Montana.
Overnight
52°F
Mostly Cloudy
Mostly cloudy, with a low around 52. Northeast wind around 12 mph, with gusts as high as 20 mph.
7-day forecast for St. Marie
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 52°F | Mostly Cloudy | 12 mph NE | 0% |
| Saturday | 67°F | Mostly Cloudy | 13 to 16 mph NE | 0% |
| Saturday Night | 48°F | Mostly Cloudy then Slight Chance Rain Showers | 13 mph E | 18% |
| Sunday | 62°F | Patchy Fog then Mostly Cloudy | 14 mph ESE | 24% |
| Sunday Night | 46°F | Partly Cloudy | 12 mph SE | 0% |
| Monday | 69°F | Mostly Sunny | 9 to 16 mph SE | 1% |
| Monday Night | 49°F | Mostly Clear | 12 to 15 mph SE | 0% |
| Tuesday | 76°F | Sunny | 12 mph SSE | 0% |
| Tuesday Night | 51°F | Mostly Clear | 8 mph SE | 1% |
| Wednesday | 78°F | Sunny | 5 to 9 mph SE | 3% |
| Wednesday Night | 52°F | Mostly Clear | 7 mph SE | 5% |
| Thursday | 80°F | Sunny | 6 to 10 mph SE | 1% |
| Thursday Night | 53°F | Mostly Clear | 9 mph ESE | 4% |
| Friday | 78°F | Sunny | 10 to 16 mph SE | 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 Sep 19, 2026.