Dewey, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Dewey, a community in Silver Bow County, Montana.
Tonight
47°F
Showers And Thunderstorms
Showers and thunderstorms. Cloudy, with a low around 47. North wind 7 to 10 mph. Chance of precipitation is 100%. New rainfall amounts between three quarters and one inch possible.
7-day forecast for Dewey
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 47°F | Showers And Thunderstorms | 7 to 10 mph N | 98% |
| Saturday | 53°F | Showers And Thunderstorms | 8 mph N | 95% |
| Saturday Night | 43°F | Chance Light Rain | 3 to 7 mph W | 40% |
| Sunday | 68°F | Mostly Sunny | 2 to 6 mph WNW | 3% |
| Sunday Night | 44°F | Mostly Clear | 6 mph SSW | 1% |
| Monday | 72°F | Sunny | 7 mph WSW | 0% |
| Monday Night | 46°F | Mostly Clear | 3 to 7 mph W | 1% |
| Tuesday | 73°F | Sunny | 3 to 7 mph SW | 2% |
| Tuesday Night | 46°F | Partly Cloudy | 3 to 7 mph WSW | 3% |
| Wednesday | 73°F | Sunny | 6 to 10 mph SW | 2% |
| Wednesday Night | 46°F | Mostly Clear | 5 to 8 mph SW | 2% |
| Thursday | 75°F | Sunny | 6 to 12 mph S | 1% |
| Thursday Night | 47°F | Partly Cloudy | 9 mph S | 1% |
| Friday | 75°F | Mostly Sunny | 8 to 13 mph SSW | 2% |
Forecast source: National Weather Service (api.weather.gov) for Dewey (45.775, -112.853). Updated through the day.
Growing snapshot for Dewey
Last spring frost
Jun 10
First fall frost
Sep 7
Growing season
85 days
Hardiness zone
5a
More local growing data for Dewey: nearby ZIP 59727 weather · frost dates · planting calendar · Montana frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Divide, Mt (5 mi from Dewey). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.