Hourly Weather | Today Sunday, January 18, 2026
San Mateo, California
11 PM
Cloudy Night
50°
Feels Like 48°
0
Humidity: 96%
Wind: 6 mph
UV Index: 0

Hourly Air Quality Forecast - AQI (US EPA)

11 PM
58 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 15.83 µg/m³
  • PM10: 22.92 µg/m³
  • O3: 0.032 ppm
  • NO2: 3.3 ppb
  • SO2: 0.5 ppb
  • CO: 0.19 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.