Bay Area PM Maps

Although the Bay Area is one of the cleanest of the five major urban air basins in California, there are still several days annually when air pollution exceeds the state or federal air quality standards.  The U.S. EPA strengthened the PM2.5 standard in 2006, which has led to an increased number of wintertime exceedances and Spare the Air Tonight episodes.

Click on a link below to view a depiction of daily particulate matter (PM) development patterns in the region.  The placemarkers showing the PM monitoring stations on a Bay Area map change color over time, reflecting the changes in AQI levels as pollution concentrations increase and subside.

Bay Area PM maps:
Today’s Maps
Today’s Current Hour Still Image
Yesterday’s Maps
Yesterday's Average
Note: Yesterday’s maps are not available until around 9am the following morning.