Grass Valley, OR Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Grass Valley, a city in Sherman County, Oregon.
Tonight
49°F
Mostly Clear
Mostly clear. Low around 49, with temperatures rising to around 51 overnight. West wind around 5 mph.
7-day forecast for Grass Valley
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 49°F | Mostly Clear | 5 mph W | 0% |
| Saturday | 76°F | Sunny | 2 to 6 mph W | 0% |
| Saturday Night | 53°F | Partly Cloudy | 0 to 3 mph S | 0% |
| Sunday | 78°F | Sunny | 0 to 7 mph SW | 0% |
| Sunday Night | 55°F | Mostly Clear | 1 to 7 mph NW | 0% |
| Monday | 78°F | Sunny | 1 to 9 mph W | 0% |
| Monday Night | 51°F | Partly Cloudy | 3 to 9 mph W | 0% |
| Tuesday | 73°F | Mostly Sunny | 3 to 13 mph W | 0% |
| Tuesday Night | 48°F | Partly Cloudy | 3 to 13 mph W | 0% |
| Wednesday | 70°F | Mostly Sunny | 3 to 7 mph W | 0% |
| Wednesday Night | 50°F | Partly Cloudy | 0 to 7 mph W | 1% |
| Thursday | 72°F | Mostly Sunny | 1 to 8 mph NW | 2% |
| Thursday Night | 50°F | Partly Cloudy | 2 to 8 mph NW | 6% |
| Friday | 65°F | Mostly Sunny | 3 to 14 mph W | 5% |
Forecast source: National Weather Service (api.weather.gov) for Grass Valley (45.359, -120.784). Updated through the day.
Growing snapshot for Grass Valley
Last spring frost
May 15
First fall frost
Oct 11
Growing season
147 days
Hardiness zone
7a
More local growing data for Grass Valley: nearby ZIP 97029 weather · frost dates · planting calendar · Oregon frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Kent, Or (9.1 mi from Grass Valley). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.