Hourly Weather | Today Tuesday, August 4, 2026
San Mateo, California
8 PM
Sunny Weather
66°
Feels Like 64°
0
Humidity: 67%
UV Index: 0
Wind: 7 mph
9 PM
Cloudy Night
66°
Feels Like 63°
0
Humidity: 67%
UV Index: 0
Wind: 6 mph
10 PM
Cloudy Night
64°
Feels Like 64°
0
Humidity: 72%
UV Index: 0
Wind: 5 mph
11 PM
Cloudy Night
63°
Feels Like 63°
0
Humidity: 77%
UV Index: 0
Wind: 4 mph

Hourly Air Quality Forecast - AQI (US EPA)

8 PM
53 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 13.58 µg/m³
  • PM10: 33.78 µg/m³
  • O3: 0.040 ppm
  • NO2: 0.4 ppb
  • SO2: 0.4 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

9 PM
56 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 14.71 µg/m³
  • PM10: 34.8 µg/m³
  • O3: 0.040 ppm
  • NO2: 0.5 ppb
  • SO2: 0.4 ppb
  • CO: 0.08 ppm

Health Recommendations:

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

10 PM
59 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 15.98 µg/m³
  • PM10: 35.89 µg/m³
  • O3: 0.040 ppm
  • NO2: 0.5 ppb
  • SO2: 0.4 ppb
  • CO: 0.08 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 17.45 µg/m³
  • PM10: 37.26 µg/m³
  • O3: 0.041 ppm
  • NO2: 0.5 ppb
  • SO2: 0.4 ppb
  • CO: 0.08 ppm

Health Recommendations:

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