Sun River, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Sun River, a community in Cascade County, Montana.
This Afternoon
55°F
Mostly Sunny
Mostly sunny. High near 55, with temperatures falling to around 48 in the afternoon. South wind 5 to 15 mph, with gusts as high as 24 mph.
7-day forecast for Sun River
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 55°F | Mostly Sunny | 5 to 15 mph S | 0% |
| Tonight | 28°F | Mostly Cloudy | 5 mph WSW | 0% |
| Wednesday | 50°F | Mostly Sunny | 2 mph WNW | 0% |
| Wednesday Night | 30°F | Mostly Clear | 1 to 7 mph SSW | 0% |
| Thursday | 56°F | Mostly Sunny | 7 to 17 mph SW | 0% |
| Thursday Night | 34°F | Mostly Clear | 14 mph SW | 0% |
| Friday | 54°F | Mostly Sunny | 12 to 25 mph SW | 1% |
| Friday Night | 37°F | Partly Cloudy | 15 to 24 mph SW | 1% |
| Saturday | 56°F | Mostly Sunny | 8 to 16 mph SW | 0% |
| Saturday Night | 37°F | Partly Cloudy | 8 to 14 mph SSW | 0% |
| Sunday | 62°F | Partly Sunny | 14 to 20 mph SW | 0% |
| Sunday Night | 38°F | Mostly Cloudy | 6 to 14 mph SW | 1% |
| Monday | 56°F | Partly Sunny | 7 mph SW | 1% |
| Monday Night | 38°F | Mostly Cloudy | 6 to 9 mph SSW | 1% |
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
Belt
Big Stone Colony
Black Eagle
Cascade
Cascade Colony
Centerville
Fair Haven Colony
Fairfield
Fort Shaw
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 Nov 4, 2026.