Alta Sierra, CA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Alta Sierra, a community in Nevada County, California.
Tonight
40°F
Patchy Fog
Patchy fog before 2am. Mostly clear, with a low around 40. Northeast wind 1 to 5 mph.
7-day forecast for Alta Sierra
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 40°F | Patchy Fog | 1 to 5 mph NE | 1% |
| Wednesday | 64°F | Sunny | 1 to 6 mph NNW | 1% |
| Wednesday Night | 42°F | Patchy Fog then Mostly Cloudy | 3 mph NE | 1% |
| Thursday | 68°F | Sunny | 3 mph NW | 0% |
| Thursday Night | 43°F | Mostly Clear | 5 mph NE | 0% |
| Friday | 69°F | Sunny | 0 to 5 mph NNE | 0% |
| Friday Night | 45°F | Mostly Clear | 0 to 3 mph NE | 0% |
| Saturday | 72°F | Sunny | 0 to 5 mph NNE | 0% |
| Saturday Night | 47°F | Mostly Clear | 0 to 5 mph NE | 0% |
| Sunday | 73°F | Sunny | 0 to 5 mph NW | 0% |
| Sunday Night | 47°F | Partly Cloudy | 0 to 5 mph NE | 0% |
| Monday | 70°F | Mostly Sunny | 0 to 5 mph S | 1% |
| Monday Night | 46°F | Partly Cloudy | 2 mph E | 1% |
| Tuesday | 70°F | Sunny then Slight Chance Light Rain | 0 to 5 mph S | 15% |
Forecast source: National Weather Service (api.weather.gov) for Alta Sierra (39.126, -121.049). Updated through the day.
Growing snapshot for Alta Sierra
Last spring frost
Apr 10
First fall frost
Nov 13
Growing season
215 days
Hardiness zone
9b
More local growing data for Alta Sierra: nearby ZIP 95949 weather · frost dates · planting calendar · California frost dates
Nearby towns & communities
Floriston
Graniteville
Grass Valley
Lake Wildwood
Nevada City
Penn Valley
Rough and Ready
Truckee
Washington
Climate data from the nearest NOAA station, Grass Valley #2, Ca (7.8 mi from Alta Sierra). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.