Grass Valley, OR Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Grass Valley, a city in Sherman County, Oregon.
Today
49°F
Slight Chance Rain Showers
A slight chance of rain showers before 1pm. Mostly cloudy. High near 49, with temperatures falling to around 42 in the afternoon. Northeast wind 5 to 9 mph. Chance of precipitation is 20%.
7-day forecast for Grass Valley
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 49°F | Slight Chance Rain Showers | 5 to 9 mph NE | 15% |
| Tonight | 34°F | Partly Cloudy | 1 to 5 mph S | 2% |
| 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% |
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 3, 2026.