The highest AQ index in California (as of 14:00 PST) is currently the Coachella Vly area. Particle Pollution (PM10) is measuring at 168 (Unhealthy). This means some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects.
Over the next few days, the highest Particle Pollution (PM2.5) will be in the Portola area. It is forecasted to be Moderate, meaning air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution.
Monday, February 16: Light southerly morning winds will limit dispersion in Portola, allowing pollutants to build up. However, as a cold front advances through the region, winds will shift to westerly and strengthen in the afternoon and evening, dispersing pollutants. Additionally, periods of precipitation will enhance atmospheric mixing. As a result, AQI levels will be low-Moderate. Tuesday, February 17: A deep upper-level trough of low pressure will keep the atmosphere well mixed over Portola. Furthermore, moderate and gusty southwesterly winds and heavy snowfall will effectively disperse pollutants, lowering AQI levels to Good. Wednesday and Thursday, as upper-level low pressure remains over northern California, snow showers will enhance atmospheric mixing. In addition, moderate southwesterly winds will disperse pollutants each afternoon. However, lighter winds during the morning and evening will lead to pollutant build-up in Portola. As a result, AQI levels will increase to low-Moderate on both days. Friday and Saturday, calm to light southwesterly winds through much of the period will reduce pollutant dispersion in Portola. Furthermore, overnight temperatures in the teens will generate an inversion each night, confining pollutants to the lower levels of the atmosphere. Therefore, AQI levels will increase to mid-Moderate on both days.
| 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 10 minutes ago
Below is a list of counties in California. Click on any county below and you'll get a list of cities where we provide AQ index forecasts.