St. Mary, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for St. Mary, a community in Glacier County, Montana.
Overnight
37°F
Mostly Clear
Mostly clear, with a low around 37. South southwest wind around 2 mph.
7-day forecast for St. Mary
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 37°F | Mostly Clear | 2 mph SSW | 0% |
| Tuesday | 72°F | Mostly Sunny | 1 to 6 mph SSW | 1% |
| Tuesday Night | 44°F | Mostly Clear | 6 mph SW | 1% |
| Wednesday | 78°F | Sunny | 3 to 8 mph WSW | 0% |
| Wednesday Night | 50°F | Mostly Clear | 7 mph WSW | 0% |
| Thursday | 85°F | Sunny | 5 to 9 mph W | 0% |
| Thursday Night | 50°F | Mostly Clear | 2 to 8 mph WSW | 0% |
| Friday | 85°F | Sunny | 1 to 13 mph WSW | 0% |
| Friday Night | 52°F | Clear | 3 to 12 mph WSW | 0% |
| Saturday | 82°F | Sunny | 2 to 12 mph WSW | 0% |
| Saturday Night | 50°F | Mostly Clear | 2 to 9 mph W | 0% |
| Sunday | 78°F | Mostly Sunny | 1 to 8 mph WSW | 3% |
| Sunday Night | 48°F | Partly Cloudy | 2 to 7 mph NNE | 13% |
| Monday | 77°F | Partly Sunny then Slight Chance Showers And Thunderstorms | 1 to 7 mph ESE | 21% |
Forecast source: National Weather Service (api.weather.gov) for St. Mary (48.743, -113.427). Updated through the day.
Growing snapshot for St. Mary
Last spring frost
Jun 3
First fall frost
Sep 8
Growing season
94 days
Hardiness zone
4b
More local growing data for St. Mary: nearby ZIP 59434 weather · frost dates · planting calendar · Montana frost dates
Nearby towns & communities
Babb
Big Sky Colony
Blackfoot
Browning
East Glacier Park Village
Glendale Colony
Hidden Lake Colony
North Browning
Seville Colony
South Browning
Starr School
Zenith Colony
Climate data from the nearest NOAA station, St. Mary 1 Ssw, Mt (4.5 mi from St. Mary). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.