Grass Valley, OR Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Grass Valley, a city in Sherman County, Oregon.
Overnight
34°F
Mostly Clear
Mostly clear, with a low around 34. South wind around 5 mph.
7-day forecast for Grass Valley
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 34°F | Mostly Clear | 5 mph S | 0% |
| Wednesday | 51°F | Mostly Sunny | 2 to 6 mph SW | 10% |
| Wednesday Night | 39°F | Chance Rain Showers | 2 to 9 mph SW | 34% |
| Thursday | 53°F | Mostly Sunny | 2 to 8 mph W | 2% |
| Thursday Night | 36°F | Partly Cloudy | 3 mph SW | 0% |
| Friday | 55°F | Mostly Cloudy | 6 mph SW | 1% |
| Friday Night | 38°F | Mostly Cloudy | 3 mph S | 1% |
| Saturday | 56°F | Mostly Sunny | 5 mph E | 1% |
| Saturday Night | 40°F | Mostly Cloudy then Slight Chance Rain Showers | 1 to 9 mph SW | 15% |
| Sunday | 54°F | Slight Chance Rain Showers then Mostly Cloudy | 5 to 9 mph W | 15% |
| Sunday Night | 37°F | Mostly Cloudy | 1 to 5 mph S | 2% |
| Monday | 52°F | Mostly Cloudy | 2 mph SE | 8% |
| Monday Night | 38°F | Slight Chance Rain Showers | 2 mph SW | 16% |
| Tuesday | 56°F | Slight Chance Rain Showers | 5 mph SW | 17% |
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.