Alta Sierra, CA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Alta Sierra, a community in Nevada County, California.
This Afternoon
84°F
Sunny
Sunny, with a high near 84. West southwest wind around 6 mph.
7-day forecast for Alta Sierra
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 84°F | Sunny | 6 mph WSW | 0% |
| Tonight | 57°F | Mostly Clear | 5 mph ENE | 0% |
| Sunday | 83°F | Partly Sunny | 5 mph SSW | 0% |
| Sunday Night | 58°F | Mostly Cloudy | 2 mph ENE | 0% |
| Monday | 82°F | Mostly Sunny | 1 to 6 mph SE | 0% |
| Monday Night | 56°F | Mostly Clear | 0 to 5 mph E | 0% |
| Tuesday | 82°F | Sunny | 0 to 6 mph WSW | 0% |
| Tuesday Night | 56°F | Mostly Clear | 3 mph ESE | 0% |
| Wednesday | 86°F | Sunny | 1 to 5 mph W | 0% |
| Wednesday Night | 58°F | Mostly Clear | 3 mph NNW | 0% |
| Thursday | 90°F | Sunny | 2 to 6 mph SSW | 0% |
| Thursday Night | 59°F | Mostly Clear | 5 mph ESE | 0% |
| Friday | 86°F | Sunny | 6 mph SSE | 0% |
| Friday Night | 58°F | Mostly Clear | 5 mph SSE | 1% |
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 Sep 19, 2026.