Sumpter, OR Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Sumpter, a city in Grant County, Oregon.
Overnight
38°F
Mostly Clear
Mostly clear, with a low around 38. North northwest wind around 2 mph.
7-day forecast for Sumpter
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 38°F | Mostly Clear | 2 mph NNW | 1% |
| Saturday | 73°F | Sunny | 1 to 5 mph N | 1% |
| Saturday Night | 43°F | Partly Cloudy | 2 mph NNW | 1% |
| Sunday | 76°F | Sunny | 1 to 5 mph E | 0% |
| Sunday Night | 44°F | Mostly Clear | 2 mph SSE | 0% |
| Monday | 76°F | Sunny | 2 mph SE | 0% |
| Monday Night | 45°F | Partly Cloudy | 1 mph WSW | 0% |
| Tuesday | 76°F | Sunny | 0 to 5 mph WSW | 1% |
| Tuesday Night | 46°F | Mostly Clear | 1 mph NW | 1% |
| Wednesday | 76°F | Sunny | 0 to 5 mph SW | 2% |
| Wednesday Night | 45°F | Partly Cloudy | 0 to 3 mph NW | 2% |
| Thursday | 75°F | Mostly Sunny | 0 to 5 mph SSE | 1% |
| Thursday Night | 45°F | Partly Cloudy | 0 to 3 mph NE | 2% |
| Friday | 70°F | Mostly Sunny | 0 to 5 mph SW | 7% |
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 Sep 19, 2026.