Frost dates for Simi Valley, California
In a typical year, Simi Valley’s last spring frost lands around Jan 8 and the first fall frost around Jan 1, a growing season of about 358 days. These are odds drawn from 30-year NOAA climate normals, not a promise. USDA zone 10a.
Right now the growing season is open, with about 68 days until the typical first fall frost.
| Odds | Last spring frost | First fall frost |
|---|---|---|
| 10 percent | Dec 8 | Nov 30 |
| 50 percent | Jan 8 | Jan 1 |
| 90 percent | Mar 10 | Feb 25 |
A 10 percent year is an early year, a 90 percent year a late one. Frost-sensitive planting usually waits for the 90 percent side of the last-frost band.
Soil in Simi Valley is typically around 67°F at 4 inches this time of year, estimated from the last two weeks of normal air temperatures.
Plantable now in Simi Valley
- Radish (Cherry Belle)
- Lettuce (Buttercrunch)
- Beet (Detroit Dark Red)
- Spinach (Space)
- Swiss chard (Bright Lights)
- Kale (Lacinato)
- Pea (Sugar Ann)
- Dill (Bouquet)
Timing comes from the same temperature engine the app uses, run against Simi Valley’s normals for today.
Common questions
When is the last frost in Simi Valley, California?
Simi Valley’s last spring frost falls around January 8 in a typical year. One year in ten it is done by December 8, and one year in ten frost holds on until March 10. Frost-sensitive planting usually waits for the late side of that band.
When is the first fall frost in Simi Valley?
The first fall frost arrives around January 1 in a typical year, as early as November 30 in an early year and as late as February 25 in a late one.
How long is the growing season in Simi Valley?
About 358 days, counted between the typical last spring frost and the typical first fall frost.
What USDA zone is Simi Valley in?
Simi Valley is in USDA hardiness zone 10a under the 2023 USDA Plant Hardiness Zone Map.
Dates come from 30-year NOAA climate normals for the nearest reporting station. They describe odds, not a forecast.
Nearby cities
- Thousand Oaks, CA (around Jan 24 to Dec 15)
- Santa Clarita, CA (around Jan 8 to Jan 1)
- Oxnard, CA (around Dec 29 to Dec 24)
- Glendale, CA (around Jan 2 to Dec 26)
- Los Angeles, CA (around Jan 8 to Jan 7)
Row & Bed is a plant reference built around your garden: your zone, your frost dates, your forecast, and a cited page for every variety in your beds.
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