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South Glastonbury, MT Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for South Glastonbury, a community in Park County, Montana.

This Afternoon
59°F
Patchy Fog
Patchy fog and showers and thunderstorms before 5pm, then a chance of showers and thunderstorms. Cloudy, with a high near 59. Northeast wind around 10 mph. Chance of precipitation is 80%.

7-day forecast for South Glastonbury

WhenTempForecastWindPrecip
This Afternoon 59°F Patchy Fog 10 mph NE 82%
Tonight 44°F Chance Showers And Thunderstorms 1 to 9 mph SE 50%
Sunday 64°F Areas Of Fog then Partly Sunny 1 to 9 mph ENE 10%
Sunday Night 42°F Partly Cloudy 6 mph S 2%
Monday 73°F Sunny 3 to 9 mph SSE 4%
Monday Night 45°F Mostly Clear 6 to 9 mph SSW 0%
Tuesday 77°F Sunny 5 to 12 mph S 1%
Tuesday Night 49°F Partly Cloudy 6 to 9 mph SSW 11%
Wednesday 76°F Mostly Sunny then Slight Chance Rain Showers 8 to 13 mph SSW 15%
Wednesday Night 48°F Mostly Clear 8 to 16 mph SSW 7%
Thursday 79°F Sunny 14 to 20 mph SSW 1%
Thursday Night 50°F Mostly Clear 10 to 20 mph SSW 1%
Friday 79°F Mostly Sunny 17 mph SSW 2%
Friday Night 49°F Partly Cloudy 12 to 17 mph S 8%

Forecast source: National Weather Service (api.weather.gov) for South Glastonbury (45.312, -110.808). Updated through the day.

Growing snapshot for South Glastonbury

Last spring frost
May 21
First fall frost
Sep 27
Growing season
128 days
Hardiness zone
5a

More local growing data for South Glastonbury: nearby ZIP 59027 weather · frost dates · planting calendar · Montana frost dates

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Climate data from the nearest NOAA station, Gardiner, Mt (18.5 mi from South Glastonbury). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 20, 2026.