Simi Valley, CA Weather & Growing Conditions
Tonight
57°F
Mostly Clear
Mostly clear, with a low around 57. North northeast wind around 5 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 57°F | Mostly Clear | 5 mph NNE | 0% |
| Saturday | 86°F | Sunny | 0 to 10 mph WSW | 0% |
| Saturday Night | 58°F | Mostly Cloudy then Patchy Fog | 5 mph E | 0% |
| Sunday | 84°F | Patchy Fog then Partly Sunny | 5 to 10 mph S | 0% |
| Sunday Night | 56°F | Partly Cloudy | 0 to 5 mph SSE | 1% |
| Monday | 80°F | Mostly Sunny | 5 to 10 mph SSW | 0% |
| Monday Night | 58°F | Mostly Clear | 0 to 10 mph W | 0% |
| Tuesday | 81°F | Sunny | 0 to 10 mph S | 0% |
| Tuesday Night | 61°F | Clear | 0 to 10 mph N | 0% |
| Wednesday | 90°F | Sunny | 0 to 10 mph WSW | 1% |
| Wednesday Night | 64°F | Mostly Clear | 0 to 10 mph N | 2% |
| Thursday | 90°F | Sunny | 0 to 10 mph SSW | 1% |
| Thursday Night | 65°F | Mostly Clear | 0 to 10 mph NE | 1% |
| Friday | 88°F | Sunny | 0 to 10 mph WSW | 1% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Simi Valley, CA
Last spring frost
Jan 24
First fall frost
Dec 15
Growing season
329 days
Hardiness zone
10a
Explore more for Simi Valley, CA: full frost dates · planting calendar · California frost dates
Climate data from the nearest NOAA station, Woodland Hills Pierce College, Ca (12.6 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.