Grass Valley, California Weather
Coastal fog thickens at dawn. Day 77 of spring. Read this microseason across nine climate regions →
Grass Valley weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Clear——85°65°—
- FridayJun 5Overcast——86°66°+1°
- SaturdayJun 6Overcast——76°55°-10°
- SundayJun 7Overcast——77°49°+1°
- MondayJun 8Rain22%0.84″61°50°-16°
- TuesdayJun 9Drizzle18%0.17″61°51°0°
- WednesdayJun 10Clear——69°47°+8°
PM2.5 at 12.1 µg/m³ (AQI 57) with a 0.79 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust. AQI down 23 over the last 6 hours — air quality is improving sharply.
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 12.1 µg/m³ (AQI 57) with a 0.79 fine-to-coarse ratio and 5 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).
A summer fog for fair, a winter fog for rain.
- Moonrise
- 6:34 AM
- Moonset
- 4:14 PM
- In sign
- ♑︎ Capricorn
Coastal fog thickens at dawn
Grass Valley at a glance
- Today vs. normal: 10°F below the seasonal normal for this latitude
- Last frost: April 11 (climatological average for this latitude)
- Microseason: Jun 1–5
- Planting window: Harvest spring lettuce before it bolts. Sow heat-tolerant greens.
Right now in the garden
Peak growing season
As of June 4, 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.