Hourly Weather | Today Tuesday, December 9, 2025
San Mateo, California
6 PM
Cloudy Night
50°
Feels Like 48°
0
Humidity: 94%
Wind: 6 mph
UV Index: 0
7 PM
Cloudy Night
48°
Feels Like 46°
0
Humidity: 91%
Wind: 6 mph
UV Index: 0
8 PM
Cloudy Night
48°
Feels Like 46°
0
Humidity: 93%
Wind: 6 mph
UV Index: 0
9 PM
Cloudy Night
48°
Feels Like 46°
0
Humidity: 93%
Wind: 5 mph
UV Index: 0
10 PM
Cloudy Night
48°
Feels Like 46°
0
Humidity: 92%
Wind: 5 mph
UV Index: 0
11 PM
Cloudy Night
46°
Feels Like 46°
0
Humidity: 93%
Wind: 5 mph
UV Index: 0

Hourly Air Quality Forecast - AQI (US EPA)

6 PM
41 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 1.96 µg/m³
  • PM10: 7.39 µg/m³
  • O3: 0.044 ppm
  • NO2: 0.4 ppb
  • SO2: 0.2 ppb
  • CO: 0.09 ppm

Health Recommendations:

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

7 PM
40 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 1.96 µg/m³
  • PM10: 7.39 µg/m³
  • O3: 0.043 ppm
  • NO2: 0.5 ppb
  • SO2: 0.2 ppb
  • CO: 0.09 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.99 µg/m³
  • PM10: 7.45 µg/m³
  • O3: 0.042 ppm
  • NO2: 0.5 ppb
  • SO2: 0.2 ppb
  • CO: 0.09 ppm

Health Recommendations:

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

9 PM
38 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 2.14 µg/m³
  • PM10: 7.85 µg/m³
  • O3: 0.041 ppm
  • NO2: 0.6 ppb
  • SO2: 0.2 ppb
  • CO: 0.09 ppm

Health Recommendations:

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

10 PM
36 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 2.38 µg/m³
  • PM10: 8.45 µg/m³
  • O3: 0.039 ppm
  • NO2: 0.8 ppb
  • SO2: 0.2 ppb
  • CO: 0.09 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.68 µg/m³
  • PM10: 9.24 µg/m³
  • O3: 0.038 ppm
  • NO2: 1 ppb
  • SO2: 0.3 ppb
  • CO: 0.10 ppm

Health Recommendations:

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