Princeton, California Weather
Summer heat deepens across the valleys. Day 15 of summer. Read this microseason across nine climate regions →
Princeton weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 5Overcast——91°62°—
- MondayJul 6Clear——92°61°+1°
- TuesdayJul 7Overcast——99°55°+7°
- WednesdayJul 8Clear——104°56°+5°
- ThursdayJul 9Clear——105°63°+1°
- FridayJul 10Overcast——107°63°+2°
- SaturdayJul 11Overcast——110°66°+3°
AQI 29 (Good), driven by PM2.5. AQI down 5 over the last 6 hours (gradual decline). PM2.5 at 9.1 µg/m³ (AQI 51) with a 0.76 fine-to-coarse ratio and 1 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
Ozone × UV × Sky
Ozone at AQI 36. Overcast through the UV peak window (cloud cover ~75%) — afternoon ozone should stay flat.
- Present
- AQI 36
- UV peak
- 6.6 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 16
PM × Wind × Precip
PM2.5 at 9.1 µg/m³ (AQI 51) with a 0.76 fine-to-coarse ratio and 1 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.76
- Wind
- calm
- 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
- 11:28 PM
- Moonset
- 11:26 AM
- In sign
- ♓︎ Pisces
Summer heat deepens across the valleys
Princeton at a glance
- Today vs. normal: 4°F above the seasonal normal for this latitude
- Last frost: April 12 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
ZIP code: 95970
16-Day Forecast — Princeton
- Sun92°62°0%
- Mon92°61°1%
- Tue99°55°0%
- Wed104°56°0%
- Thu105°63°0%
- Fri107°63°0%
- Sat110°66°1%
- Sun111°66°1%
- Mon114°75°2%
- Tue117°74°2%
- Wed103°77°1%
- Thu99°80°2%
- Fri110°72°3%
- Sat117°73°3%
- Sun118°73°3%
- Mon109°64°3%
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 Princeton
- 95970
- 95932