Penn Valley, CA Weather & Growing Conditions
Tonight
42°F
Patchy Fog then Haze
Patchy fog between 9pm and 10pm, then haze and areas of fog between 10pm and 1am. Mostly cloudy, with a low around 42. Northeast wind 0 to 5 mph. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 42°F | Patchy Fog then Haze | 0 to 5 mph NE | 10% |
| Wednesday | 63°F | Sunny | 2 to 6 mph NNW | 0% |
| Wednesday Night | 43°F | Partly Cloudy | 3 mph NE | 0% |
| Thursday | 66°F | Sunny | 1 to 5 mph WNW | 0% |
| Thursday Night | 44°F | Mostly Clear | 1 to 5 mph N | 0% |
| Friday | 68°F | Sunny | 1 to 5 mph W | 0% |
| Friday Night | 47°F | Mostly Clear | 3 mph ENE | 0% |
| Saturday | 71°F | Sunny | 1 to 5 mph SW | 0% |
| Saturday Night | 49°F | Mostly Clear | 3 mph E | 0% |
| Sunday | 71°F | Mostly Sunny | 1 to 5 mph W | 0% |
| Sunday Night | 50°F | Partly Cloudy | 2 mph SSE | 0% |
| Monday | 69°F | Partly Sunny | 3 mph SSE | 4% |
| Monday Night | 50°F | Partly Cloudy | 2 mph E | 4% |
| Tuesday | 69°F | Mostly Sunny | 3 mph E | 9% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Penn Valley, CA
Last spring frost
Apr 10
First fall frost
Nov 13
Growing season
215 days
Hardiness zone
9b
Explore more for Penn Valley, CA: full frost dates · planting calendar · California frost dates
Climate data from the nearest NOAA station, Grass Valley #2, Ca (7.8 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.