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Today Hourly 7 days 30 days Air Quality
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Hourly Weather | Today | Friday, August 22, 2025
San Mateo, California
8 AM
Cloudy WeatherCloudy weather, overcast skies with clouds.
59°
Feels Like 61°
0
Humidity: 90%
Wind: 6 mph
UV Index: 16
9 AM
Cloudy WeatherCloudy weather, overcast skies with clouds.
63°
Feels Like 64°
0
Humidity: 81%
Wind: 7 mph
UV Index: 26
10 AM
Cloudy WeatherCloudy weather, overcast skies with clouds.
66°
Feels Like 70°
0
Humidity: 74%
Wind: 7 mph
UV Index: 40
11 AM
Cloudy WeatherCloudy weather, overcast skies with clouds.
70°
Feels Like 73°
0
Humidity: 68%
Wind: 7 mph
UV Index: 56
12 PM
Cloudy WeatherCloudy weather, overcast skies with clouds.
72°
Feels Like 79°
0
Humidity: 62%
Wind: 8 mph
UV Index: 76
1 PM
Cloudy WeatherCloudy weather, overcast skies with clouds.
73°
Feels Like 81°
0
Humidity: 58%
Wind: 9 mph
UV Index: 84
2 PM
Cloudy WeatherCloudy weather, overcast skies with clouds.
77°
Feels Like 82°
0
Humidity: 53%
Wind: 10 mph
UV Index: 76
3 PM
Cloudy WeatherCloudy weather, overcast skies with clouds.
75°
Feels Like 79°
0
Humidity: 55%
Wind: 12 mph
UV Index: 56
4 PM
Cloudy WeatherCloudy weather, overcast skies with clouds.
75°
Feels Like 75°
0
Humidity: 57%
Wind: 13 mph
UV Index: 40
5 PM
Cloudy WeatherCloudy weather, overcast skies with clouds.
73°
Feels Like 73°
0
Humidity: 60%
Wind: 13 mph
UV Index: 26
6 PM
Cloudy WeatherCloudy weather, overcast skies with clouds.
72°
Feels Like 70°
0
Humidity: 64%
Wind: 12 mph
UV Index: 16
7 PM
Cloudy WeatherCloudy weather, overcast skies with clouds.
70°
Feels Like 66°
0
Humidity: 71%
Wind: 10 mph
UV Index: 6
8 PM
Cloudy NightCloudy night, overcast skies at night with no rain.
66°
Feels Like 63°
0
Humidity: 78%
Wind: 10 mph
UV Index: 0
9 PM
Cloudy NightCloudy night, overcast skies at night with no rain.
63°
Feels Like 61°
0
Humidity: 83%
Wind: 9 mph
UV Index: 0
10 PM
Cloudy NightCloudy night, overcast skies at night with no rain.
63°
Feels Like 61°
0
Humidity: 87%
Wind: 8 mph
UV Index: 0
11 PM
Cloudy NightCloudy night, overcast skies at night with no rain.
63°
Feels Like 59°
0
Humidity: 88%
Wind: 7 mph
UV Index: 0

Hourly Air Quality Forecast - AQI (US EPA)

8 AM
55 AQI
Moderate air quality Dominant pollutant: pm25
Details

Pollutant Concentrations:

  • PM2.5: 13.66 µg/m³
  • PM10: 19.00 µg/m³
  • O₃: 32.69 ppb
  • NO₂: 4.30 ppb
  • SO₂: 1.05 ppb
  • CO: 127.02 ppb

Health Recommendations:

Air quality is currently in the acceptable range. However, sensitive individuals should be aware of potential risks from certain pollutants.

9 AM
56 AQI
Moderate air quality Dominant pollutant: pm25
Details

Pollutant Concentrations:

  • PM2.5: 14.03 µg/m³
  • PM10: 19.42 µg/m³
  • O₃: 33.86 ppb
  • NO₂: 4.13 ppb
  • SO₂: 1.11 ppb
  • CO: 127.76 ppb

Health Recommendations:

Air quality is currently in the acceptable range. However, sensitive individuals should be aware of potential risks from certain pollutants.

10 AM
56 AQI
Moderate air quality Dominant pollutant: pm25
Details

Pollutant Concentrations:

  • PM2.5: 14.09 µg/m³
  • PM10: 19.40 µg/m³
  • O₃: 35.03 ppb
  • NO₂: 3.97 ppb
  • SO₂: 1.18 ppb
  • CO: 128.50 ppb

Health Recommendations:

Air quality is currently in the acceptable range. However, sensitive individuals should be aware of potential risks from certain pollutants.

11 AM
57 AQI
Moderate air quality Dominant pollutant: pm25
Details

Pollutant Concentrations:

  • PM2.5: 14.40 µg/m³
  • PM10: 19.69 µg/m³
  • O₃: 36.20 ppb
  • NO₂: 3.81 ppb
  • SO₂: 1.24 ppb
  • CO: 129.24 ppb

Health Recommendations:

Air quality is currently in the acceptable range. However, sensitive individuals should be aware of potential risks from certain pollutants.

12 PM
57 AQI
Moderate air quality Dominant pollutant: pm25
Details

Pollutant Concentrations:

  • PM2.5: 15.26 µg/m³
  • PM10: 20.66 µg/m³
  • O₃: 37.91 ppb
  • NO₂: 3.66 ppb
  • SO₂: 1.21 ppb
  • CO: 129.10 ppb

Health Recommendations:

Air quality is currently in the acceptable range. However, sensitive individuals should be aware of potential risks from certain pollutants.

1 PM
57 AQI
Moderate air quality Dominant pollutant: pm25
Details

Pollutant Concentrations:

  • PM2.5: 16.41 µg/m³
  • PM10: 21.91 µg/m³
  • O₃: 39.62 ppb
  • NO₂: 3.50 ppb
  • SO₂: 1.18 ppb
  • CO: 128.96 ppb

Health Recommendations:

Air quality is currently in the acceptable range. However, sensitive individuals should be aware of potential risks from certain pollutants.

2 PM
57 AQI
Moderate air quality Dominant pollutant: pm25
Details

Pollutant Concentrations:

  • PM2.5: 17.45 µg/m³
  • PM10: 23.06 µg/m³
  • O₃: 41.34 ppb
  • NO₂: 3.35 ppb
  • SO₂: 1.15 ppb
  • CO: 128.82 ppb

Health Recommendations:

Air quality is currently in the acceptable range. However, sensitive individuals should be aware of potential risks from certain pollutants.

3 PM
57 AQI
Moderate air quality Dominant pollutant: pm25
Details

Pollutant Concentrations:

  • PM2.5: 17.61 µg/m³
  • PM10: 23.04 µg/m³
  • O₃: 40.74 ppb
  • NO₂: 3.62 ppb
  • SO₂: 1.05 ppb
  • CO: 129.16 ppb

Health Recommendations:

Air quality is currently in the acceptable range. However, sensitive individuals should be aware of potential risks from certain pollutants.

4 PM
58 AQI
Moderate air quality Dominant pollutant: pm25
Details

Pollutant Concentrations:

  • PM2.5: 17.19 µg/m³
  • PM10: 22.24 µg/m³
  • O₃: 40.15 ppb
  • NO₂: 3.88 ppb
  • SO₂: 0.94 ppb
  • CO: 129.50 ppb

Health Recommendations:

Air quality is currently in the acceptable range. However, sensitive individuals should be aware of potential risks from certain pollutants.

5 PM
59 AQI
Moderate air quality Dominant pollutant: pm25
Details

Pollutant Concentrations:

  • PM2.5: 17.00 µg/m³
  • PM10: 21.80 µg/m³
  • O₃: 39.55 ppb
  • NO₂: 4.15 ppb
  • SO₂: 0.84 ppb
  • CO: 129.84 ppb

Health Recommendations:

Air quality is currently in the acceptable range. However, sensitive individuals should be aware of potential risks from certain pollutants.

6 PM
59 AQI
Moderate air quality Dominant pollutant: pm25
Details

Pollutant Concentrations:

  • PM2.5: 16.94 µg/m³
  • PM10: 21.48 µg/m³
  • O₃: 35.88 ppb
  • NO₂: 5.44 ppb
  • SO₂: 0.79 ppb
  • CO: 133.56 ppb

Health Recommendations:

Air quality is currently in the acceptable range. However, sensitive individuals should be aware of potential risks from certain pollutants.

7 PM
60 AQI
Moderate air quality Dominant pollutant: pm25
Details

Pollutant Concentrations:

  • PM2.5: 16.65 µg/m³
  • PM10: 20.94 µg/m³
  • O₃: 32.20 ppb
  • NO₂: 6.73 ppb
  • SO₂: 0.74 ppb
  • CO: 137.27 ppb

Health Recommendations:

Air quality is currently in the acceptable range. However, sensitive individuals should be aware of potential risks from certain pollutants.

8 PM
60 AQI
Moderate air quality Dominant pollutant: pm25
Details

Pollutant Concentrations:

  • PM2.5: 16.82 µg/m³
  • PM10: 21.10 µg/m³
  • O₃: 28.53 ppb
  • NO₂: 8.02 ppb
  • SO₂: 0.69 ppb
  • CO: 140.99 ppb

Health Recommendations:

Air quality is currently in the acceptable range. However, sensitive individuals should be aware of potential risks from certain pollutants.

9 PM
61 AQI
Moderate air quality Dominant pollutant: pm25
Details

Pollutant Concentrations:

  • PM2.5: 17.26 µg/m³
  • PM10: 21.62 µg/m³
  • O₃: 26.89 ppb
  • NO₂: 8.31 ppb
  • SO₂: 0.70 ppb
  • CO: 143.96 ppb

Health Recommendations:

Air quality is currently in the acceptable range. However, sensitive individuals should be aware of potential risks from certain pollutants.

Current Real-Time Air Quality Report