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
34°F
Mostly Clear
Mostly clear, with a low around 34. South wind 1 to 5 mph.
7-day forecast for Grass Valley
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 34°F | Mostly Clear | 1 to 5 mph S | 1% |
| Wednesday | 52°F | Sunny | 2 to 6 mph SW | 9% |
| Wednesday Night | 40°F | Rain Showers Likely | 2 to 8 mph SW | 62% |
| Thursday | 53°F | Mostly Sunny | 3 to 9 mph W | 1% |
| Thursday Night | 38°F | Mostly Cloudy | 3 mph SW | 4% |
| Friday | 55°F | Mostly Cloudy | 3 to 7 mph SW | 4% |
| Friday Night | 39°F | Mostly Cloudy | 3 mph SW | 3% |
| Saturday | 57°F | Partly Sunny | 5 mph SE | 1% |
| Saturday Night | 41°F | Mostly Cloudy then Slight Chance Rain Showers | 2 to 9 mph SW | 16% |
| Sunday | 55°F | Slight Chance Rain Showers | 5 to 10 mph SW | 16% |
| Sunday Night | 39°F | Mostly Cloudy | 1 to 5 mph S | 10% |
| Monday | 53°F | Mostly Cloudy | 3 mph SE | 10% |
| Monday Night | 40°F | Mostly Cloudy then Slight Chance Rain Showers | 3 mph W | 18% |
| Tuesday | 57°F | Chance Rain Showers | 6 mph SW | 28% |
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 Nov 4, 2026.