Castaic, California Weather
Summer heat deepens across the valleys. Day 15 of summer. Read this microseason across nine climate regions →
Castaic weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 5Overcast——85°63°—
- MondayJul 6Clear——86°60°+1°
- TuesdayJul 7Clear——94°64°+8°
- WednesdayJul 8Clear——97°67°+3°
- ThursdayJul 9Clear——99°69°+2°
- FridayJul 10Clear——97°64°-2°
- SaturdayJul 11Overcast——96°64°-1°
AQI 45 (Good), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 10.8 µg/m³ (AQI 54) with a 0.79 fine-to-coarse ratio and 6 mph wind — combustion smoke trapped in calm air, not road dust.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
PM × Wind × Precip
PM2.5 at 10.8 µg/m³ (AQI 54) with a 0.79 fine-to-coarse ratio and 6 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.79
- Wind
- light
- Recent rain
- 0h in last 6h
- Pattern
- stagnant smoke
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).
If the first of July be rainy weather, 'twill rain more or less for four weeks together.
- Moonrise
- 11:11 PM
- Moonset
- 11:13 AM
- In sign
- ♓︎ Pisces
Summer heat deepens across the valleys
Castaic at a glance
- Today vs. normal: 78°F — typical for the season
- Last frost: March 14 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
ZIP code: 91384
16-Day Forecast — Castaic
- Sun85°63°1%
- Mon86°60°0%
- Tue94°64°0%
- Wed97°67°0%
- Thu99°69°0%
- Fri97°64°0%
- Sat96°64°1%
- Sun99°67°1%
- Mon100°67°4%
- Tue98°71°7%
- Wed99°73°1%
- Thu101°74°10%
- Fri108°78°9%
- Sat116°84°6%
- Sun99°76°10%
- Mon100°70°10%
Forecast data from Open-Meteo (CC BY 4.0).
Right now in the garden
Peak growing season
As of July 5, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.
ZIP codes in Castaic
- 91384
- 91310