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
41°F
Partly Cloudy
Partly cloudy, with a low around 41. West wind around 6 mph.
7-day forecast for St. Marie
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 41°F | Partly Cloudy | 6 mph W | 0% |
| Tuesday | 73°F | Sunny | 6 to 14 mph WNW | 0% |
| Tuesday Night | 50°F | Mostly Clear | 2 to 12 mph SW | 1% |
| Wednesday | 82°F | Partly Sunny | 5 to 16 mph WSW | 0% |
| Wednesday Night | 53°F | Partly Cloudy | 2 to 15 mph N | 0% |
| Thursday | 88°F | Sunny | 2 to 12 mph WNW | 0% |
| Thursday Night | 55°F | Mostly Clear | 9 to 13 mph N | 0% |
| Friday | 87°F | Sunny | 8 mph ESE | 0% |
| Friday Night | 56°F | Mostly Clear | 7 to 13 mph ENE | 1% |
| Saturday | 87°F | Sunny | 12 mph E | 0% |
| Saturday Night | 58°F | Partly Cloudy | 9 to 15 mph NE | 2% |
| Sunday | 85°F | Partly Sunny | 14 mph ENE | 3% |
| Sunday Night | 57°F | Partly Cloudy | 12 to 16 mph NE | 14% |
| Monday | 82°F | Slight Chance Rain Showers then Slight Chance Showers And Thunderstorms | 15 mph ENE | 23% |
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 Aug 4, 2026.