St. Mary, MT Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for St. Mary, a community in Glacier County, Montana.

Tonight

28°F

Mostly Cloudy

Mostly cloudy, with a low around 28. West southwest wind around 5 mph.

7-day forecast for St. Mary

When	Temp	Forecast	Wind	Precip
Tonight	28°F	Mostly Cloudy	5 mph WSW	0%
Wednesday	51°F	Mostly Sunny	3 mph W	0%
Wednesday Night	31°F	Mostly Clear	3 to 10 mph SW	1%
Thursday	44°F	Mostly Sunny then Slight Chance Light Snow	10 to 14 mph WSW	16%
Thursday Night	32°F	Slight Chance Light Snow then Mostly Cloudy	12 to 16 mph WSW	16%
Friday	43°F	Slight Chance Light Rain then Chance Rain And Snow	18 mph WSW	31%
Friday Night	32°F	Chance Rain And Snow then Mostly Cloudy	13 to 21 mph WSW	31%
Saturday	48°F	Partly Sunny	8 to 13 mph SW	2%
Saturday Night	35°F	Mostly Cloudy	8 to 12 mph SW	13%
Sunday	52°F	Chance Light Rain	10 to 15 mph SW	37%
Sunday Night	34°F	Chance Rain And Snow	6 to 14 mph WSW	31%
Monday	49°F	Partly Sunny	8 mph SW	10%
Monday Night	35°F	Slight Chance Rain And Snow	7 to 12 mph SW	19%
Tuesday	50°F	Chance Rain And Snow	10 to 14 mph SW	30%

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

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

All Montana locations ›

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 Nov 4, 2026.