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The area with the highest AQ Index (as of 23:00 PDT) in is in the Redwood City area. Particle Pollution (PM2.5) is measuring at 56 (Moderate). This means air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution.
Over the next few days, the highest primary air pollutant will be Ozone (OZONE) in the Redwood City area. It is forecasted to be 67 (Moderate), meaning air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution.
Below is a clickable map of San Mateo County, California. The markers on the map identify large, populated cities. If you hover over a marker, it will display the city name and the current AQ index. The color of the city markers also references the current AQ risk level.
| Range | 0 - 50 | 51 - 100 | 101 - 150 | 151 - 200 | 201 - 300 | 301 - 500 |
| Color | ||||||
| Category | Good | Moderate | Unhealthy for Sensitive Groups | Unhealthy | Very Unhealthy | Hazardous |
Last Updated 5 minutes ago
Below is a list of cities in San Mateo County where we track and forecast the AQ index. Click on a city name to get the current AQ index as well as any available forcasts.