Castaic, CA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Castaic, a community in Los Angeles County, California.
This Afternoon
86°F
Sunny
Sunny, with a high near 86. Southwest wind 5 to 15 mph, with gusts as high as 20 mph.
7-day forecast for Castaic
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 86°F | Sunny | 5 to 15 mph SW | 0% |
| Tonight | 53°F | Partly Cloudy | 0 to 5 mph NNW | 0% |
| Sunday | 84°F | Mostly Sunny | 0 to 10 mph SSW | 0% |
| Sunday Night | 51°F | Mostly Cloudy then Patchy Fog | 0 to 10 mph W | 1% |
| Monday | 79°F | Patchy Fog then Mostly Sunny | 0 to 15 mph SSW | 1% |
| Monday Night | 50°F | Mostly Clear | 0 to 10 mph NW | 0% |
| Tuesday | 81°F | Sunny | 5 to 10 mph SW | 0% |
| Tuesday Night | 61°F | Clear | 0 to 10 mph NNW | 0% |
| Wednesday | 90°F | Sunny | 5 to 10 mph ESE | 0% |
| Wednesday Night | 64°F | Clear | 0 to 15 mph NNW | 0% |
| Thursday | 91°F | Sunny | 5 to 10 mph ESE | 0% |
| Thursday Night | 64°F | Mostly Clear | 0 to 10 mph WNW | 0% |
| Friday | 88°F | Sunny | 0 to 10 mph SSW | 1% |
| Friday Night | 63°F | Mostly Clear | 0 to 10 mph WNW | 1% |
Forecast source: National Weather Service (api.weather.gov) for Castaic (34.477, -118.633). Updated through the day.
Growing snapshot for Castaic
Last spring frost
Jan 8
First fall frost
Jan 1
Growing season
365 days
Hardiness zone
10a
More local growing data for Castaic: nearby ZIP 91384 weather · frost dates · planting calendar · California frost dates
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Climate data from the nearest NOAA station, Newhall 5Nw, Ca (9.7 mi from Castaic). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 20, 2026.