Sun River, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Sun River, a community in Cascade County, Montana.
Today
69°F
Mostly Cloudy
Mostly cloudy, with a high near 69. East northeast wind 5 to 8 mph.
7-day forecast for Sun River
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 69°F | Mostly Cloudy | 5 to 8 mph ENE | 12% |
| Tonight | 45°F | Mostly Cloudy | 1 to 7 mph SSE | 2% |
| Sunday | 75°F | Mostly Sunny | 1 to 6 mph S | 0% |
| Sunday Night | 46°F | Mostly Clear | 2 to 6 mph S | 0% |
| Monday | 80°F | Sunny | 2 to 7 mph SSW | 0% |
| Monday Night | 48°F | Mostly Clear | 7 mph SW | 0% |
| Tuesday | 80°F | Sunny | 5 mph WSW | 0% |
| Tuesday Night | 48°F | Mostly Clear | 6 mph SW | 0% |
| Wednesday | 81°F | Sunny | 3 to 8 mph SW | 0% |
| Wednesday Night | 49°F | Mostly Clear | 5 to 8 mph SSW | 3% |
| Thursday | 81°F | Sunny | 3 to 9 mph SSW | 2% |
| Thursday Night | 49°F | Partly Cloudy | 3 to 7 mph SSE | 6% |
| Friday | 77°F | Mostly Sunny | 3 to 10 mph SW | 7% |
| Friday Night | 47°F | Chance Light Rain | 7 to 10 mph WNW | 25% |
Forecast source: National Weather Service (api.weather.gov) for Sun River (47.531, -111.724). Updated through the day.
Growing snapshot for Sun River
Last spring frost
Jun 2
First fall frost
Sep 10
Growing season
96 days
Hardiness zone
4a
More local growing data for Sun River: nearby ZIP 59483 weather · frost dates · planting calendar · Montana frost dates
Nearby towns & communities
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Big Stone Colony
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Fairfield
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Gibson Flats
Great Falls
Hardy
Malmstrom AFB
Monarch
Neihart
Pleasant Valley Colony
Riceville
Sand Coulee
Simms
Stockett
Sun Prairie
Tracy
Ulm
Vaughn
Climate data from the nearest NOAA station, Sun Rvr 4 S, Mt (0.9 mi from Sun River). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.