CURRENT AIR QUALITY CONDITIONS
AIR QUALITY FORECASTS AND HEALTH INFO
View air quality forecast maps for:
See outlooks and smoke reports for California wildfires posted on California Smoke Information site.
AIR QUALITY INDEX
Numbers in the chart above show the Air Quality Index for today, based on an average over time. See AQI Table for how to interpret the colors. The Index numbers represent a ranking for the pollutant, not the measurement of a pollutant. When air quality is expected to be worse — such as during wildfires, which produce elevated levels of particulate matter (PM) — it is important to check hourly readings, which do show the measurement of the pollutant. Hourly readings are available on the Station Data page. The Index below presents ratings for: ozone, a principal component of smog; particulate matter smaller than 10 microns in diameter (PM10); and particulate matter smaller than 2.5 microns in diameter (PM2.5). Note: all data are preliminary and subject to verification. To view exceedances of standards, see Days Exceeding Ozone and Particulate Standards.