Sumpter, OR Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Sumpter, a city in Grant County, Oregon.
Tonight
29°F
Partly Cloudy
Partly cloudy, with a low around 29. Northwest wind around 1 mph.
7-day forecast for Sumpter
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 29°F | Partly Cloudy | 1 mph NW | 6% |
| Wednesday | 54°F | Sunny | 1 mph NW | 1% |
| Wednesday Night | 32°F | Mostly Cloudy then Slight Chance Rain And Snow Showers | 0 mph | 20% |
| Thursday | 48°F | Slight Chance Rain And Snow Showers then Partly Sunny | 0 to 3 mph WNW | 20% |
| Thursday Night | 28°F | Mostly Clear | 1 mph NW | 3% |
| Friday | 50°F | Partly Sunny | 1 mph NNE | 6% |
| Friday Night | 32°F | Partly Cloudy | 0 mph | 1% |
| Saturday | 54°F | Mostly Sunny | 0 to 6 mph SSE | 1% |
| Saturday Night | 33°F | Partly Cloudy | 3 mph SSE | 2% |
| Sunday | 53°F | Partly Sunny | 3 mph SSW | 9% |
| Sunday Night | 33°F | Mostly Cloudy | 1 mph WSW | 9% |
| Monday | 53°F | Partly Sunny | 2 mph SSE | 8% |
| Monday Night | 33°F | Mostly Cloudy | 0 mph | 10% |
| Tuesday | 54°F | Mostly Sunny then Slight Chance Rain Showers | 2 mph SE | 16% |
Forecast source: National Weather Service (api.weather.gov) for Sumpter (44.744, -118.197). Updated through the day.
Growing snapshot for Sumpter
Growing season
74 days
Hardiness zone
6b
More local growing data for Sumpter: nearby ZIP 97877 weather · frost dates · planting calendar · Oregon frost dates
Nearby towns & communities
Canyon City
Dayville
Granite
Greenhorn
John Day
Long Creek
Monument
Mount Vernon
Prairie City
Seneca
Climate data from the nearest NOAA station, Austin 3 S, Or (17 mi from Sumpter). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.