AQ Index for California

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Air Quality Index for California

The highest AQ index in California (as of 20:00 PST) is currently the Portola area. Particle Pollution (PM2.5) is measuring at 114 (Unhealthy for Sensitive Groups). This means members of sensitive groups may experience health effects. The general public is less likely to be affected.

Over the next few days, the highest Particle Pollution (PM2.5) will be in the Arden Arcade-Del Paso Manor 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.

Thursday, a temperature inversion will confine pollutants near the surface during the morning and evening hours. Additionally, light and variable winds will limit dispersion in the Sacramento region as a surface ridge of high pressure weakens to the north. Furthermore, upper-level high pressure will move across northern California, reducing vertical mixing. These conditions will lead to mid-Moderate particle levels. Friday, the morning temperature inversion will strengthen as upper-level ridging remains over northern California. In addition, areas of fog will promote particle formation, while light southeasterly winds gradually transport pollutants northward from the San Joaquin Valley during the afternoon and evening. As a result, particle levels will increase to high-Moderate. Saturday, as the ridge aloft weakens, atmospheric mixing will improve slightly across the Sacramento region. In addition, light northwesterly winds will aid dispersion during the afternoon. However, pollutant carryover from the previous day will keep particle levels elevated. Furthermore, ongoing pile burns around the region will continue to contribute to pollutant accumulation. Therefore, particle levels will remain high-Moderate.

Range0 - 5051 - 100101 - 150151 - 200201 - 300301 - 500
Color
CategoryGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardous

Last Updated 16 minutes ago

AQ Index Forecast by County in California

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.

Los Angeles San Francisco San Diego Riverside Sacramento
Santa Clara Fresno Contra Costa Orange Kern
Alameda San Joaquin Ventura Stanislaus San Bernardino
Sonoma Tulare Santa Barbara Monterey Solano
Santa Cruz Merced Placer Sutter Shasta
Butte Imperial San Mateo Kings Napa
Madera Yolo San Luis Obispo Marin El Dorado
San Benito Humboldt Yuba Nevada Mendocino
Lake Lassen Tehama Mono Amador
Glenn Siskiyou Del Norte Calaveras Colusa
Tuolumne Inyo Trinity Modoc Plumas
Mariposa Sierra Alpine