Grass Valley, CA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Grass Valley, a city in Nevada County, California.
Tonight
57°F
Clear
Clear. Low around 57, with temperatures rising to around 59 overnight. Northeast wind around 5 mph.
7-day forecast for Grass Valley
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 57°F | Clear | 5 mph NE | 0% |
| Saturday | 83°F | Sunny | 1 to 6 mph E | 0% |
| Saturday Night | 58°F | Partly Cloudy | 3 mph ENE | 0% |
| Sunday | 82°F | Partly Sunny | 1 to 5 mph E | 0% |
| Sunday Night | 59°F | Mostly Cloudy | 2 mph ENE | 0% |
| Monday | 82°F | Mostly Sunny | 0 to 5 mph NW | 0% |
| Monday Night | 58°F | Mostly Clear | 3 mph ESE | 0% |
| Tuesday | 84°F | Sunny | 1 to 5 mph WSW | 0% |
| Tuesday Night | 59°F | Clear | 3 mph ESE | 0% |
| Wednesday | 89°F | Sunny | 1 to 5 mph W | 0% |
| Wednesday Night | 61°F | Mostly Clear | 5 mph E | 0% |
| Thursday | 90°F | Sunny | 5 mph SSE | 0% |
| Thursday Night | 62°F | Mostly Clear | 5 mph SE | 0% |
| Friday | 86°F | Sunny | 5 mph SSE | 0% |
Forecast source: National Weather Service (api.weather.gov) for Grass Valley (39.220, -121.053). Updated through the day.
Growing snapshot for Grass Valley
Last spring frost
Apr 14
First fall frost
Nov 20
Growing season
218 days
Hardiness zone
9a
More local growing data for Grass Valley: nearby ZIP 95945 weather · frost dates · planting calendar · California frost dates
Nearby towns & communities
Alta Sierra
Floriston
Graniteville
Lake Wildwood
Nevada City
Penn Valley
Rough and Ready
Truckee
Washington
Climate data from the nearest NOAA station, Nevada City, Ca (3.9 mi from Grass Valley). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.