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
45°F
Mostly Cloudy
Mostly cloudy, with a low around 45. Southeast wind around 1 mph.
7-day forecast for St. Mary
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 45°F | Mostly Cloudy | 1 mph SE | 0% |
| Saturday | 67°F | Sunny | 1 to 7 mph SE | 2% |
| Saturday Night | 45°F | Mostly Clear | 6 mph S | 0% |
| Sunday | 71°F | Sunny | 5 mph SW | 0% |
| Sunday Night | 46°F | Mostly Clear | 5 mph SW | 0% |
| Monday | 71°F | Sunny | 5 to 8 mph WSW | 0% |
| Monday Night | 47°F | Mostly Clear | 7 mph WSW | 0% |
| Tuesday | 70°F | Sunny | 6 mph WSW | 0% |
| Tuesday Night | 47°F | Partly Cloudy | 5 mph SW | 0% |
| Wednesday | 69°F | Mostly Sunny | 3 to 9 mph SW | 0% |
| Wednesday Night | 47°F | Partly Cloudy | 6 mph SW | 0% |
| Thursday | 69°F | Mostly Sunny | 3 to 7 mph SW | 1% |
| Thursday Night | 47°F | Partly Cloudy | 5 mph SW | 8% |
| Friday | 64°F | Partly Sunny then Slight Chance Light Rain | 2 to 6 mph SW | 15% |
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 Sep 19, 2026.