Today | Weather | Saturday, September 19, 2026

Weather in Santa Rosa, California

05:27 AM
Now
Cloudy Weather
54° F
Feels Like 55°
Precipitation 0 %
Wind 2 mph
Humidity 94 %
Today
Cloudy Weather
Day 84°
Night 52°
Precipitation 0 %
Wind 6 mph
UV Index (0 - 11+) 5

Santa Rosa Weather Forecast Updated

37 minutes ago
Last updated on
Weather Forecast History
Last Year's Weather on This Day (September 19, 2025)
Cloudy Night

Day

81°

Night

54°

Wind

5 mph

Precipitation

2 %

Air Quality in Santa Rosa

NOW
42 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 5.42 µg/m³
PM10 20.66 µg/m³
O3 0.045 ppm
NO2 0.4 ppb
SO2 0.3 ppb
CO 0.12 ppm
NH3 0.01 µg/m³
NO 0 µg/m³
PM2.5 – Fine particles <2.5μm
PM10 – Inhalable particles <10μm
O3 – Ozone
NO2 – Nitrogen dioxide
SO2 – Sulfur dioxide
CO – Carbon monoxide
NH3 – Ammonia
NO – Nitric oxide

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

Show raw pollutant concentrations (µg/m³)
PM2.55.42 µg/m³
PM1020.66 µg/m³
O389 µg/m³
NO20.7 µg/m³
SO20.77 µg/m³
CO139.71 µg/m³
NH30.01 µg/m³
NO0 µg/m³