Hourly Weather | Today Sunday, September 13, 2026
San Mateo, California
11 PM
Cloudy Night
57°
Feels Like 55°
0
Humidity: 89%
UV Index: 0
Wind: 8 mph

Hourly Air Quality Forecast - AQI (US EPA)

11 PM
39 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 3.79 µg/m³
  • PM10: 17.17 µg/m³
  • O3: 0.042 ppm
  • NO2: 0.3 ppb
  • SO2: 0.3 ppb
  • CO: 0.17 ppm

Health Recommendations:

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