Garrison, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Garrison, a community in Powell County, Montana.
Tonight
45°F
Showers And Thunderstorms
Showers and thunderstorms. Cloudy, with a low around 45. North wind around 2 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.
7-day forecast for Garrison
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 45°F | Showers And Thunderstorms | 2 mph N | 90% |
| Saturday | 63°F | Showers And Thunderstorms | 5 mph NNE | 78% |
| Saturday Night | 40°F | Mostly Cloudy then Areas Of Fog | 2 mph SE | 9% |
| Sunday | 72°F | Patchy Fog then Sunny | 2 mph SW | 0% |
| Sunday Night | 41°F | Mostly Clear | 2 mph S | 0% |
| Monday | 76°F | Sunny | 1 to 5 mph SSW | 0% |
| Monday Night | 43°F | Mostly Clear | 0 to 5 mph SW | 0% |
| Tuesday | 76°F | Sunny | 0 to 3 mph SW | 0% |
| Tuesday Night | 44°F | Mostly Clear | 0 to 3 mph SSW | 2% |
| Wednesday | 76°F | Sunny | 1 to 5 mph SW | 2% |
| Wednesday Night | 43°F | Mostly Clear | 0 to 3 mph S | 3% |
| Thursday | 78°F | Sunny | 3 mph S | 1% |
| Thursday Night | 44°F | Partly Cloudy | 2 to 7 mph SSE | 1% |
| Friday | 78°F | Mostly Sunny | 6 mph S | 1% |
Forecast source: National Weather Service (api.weather.gov) for Garrison (46.540, -112.817). Updated through the day.
Growing snapshot for Garrison
Growing season
65 days
Hardiness zone
4b
More local growing data for Garrison: nearby ZIP 59731 weather · frost dates · planting calendar · Montana frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Deer Lodge 3 W, Mt (13.1 mi from Garrison). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.