Jump to main content or area navigation.

Contact EPA Pacific Southwest

Pacific Southwest, Region 9

Serving: Arizona, California, Hawaii, Nevada, Pacific Islands, Tribal Nations

Air Quality Analysis

Air Quality Trends (1976-2018)

8-Hour Ozone Concentrations

"Design Value" - National 8-hour Standard
Average of 4th Highest Days over Three Years

(Click Graph to Enlarge)
Graph showing air pollution concentrations for ozone - Click to Enlarge
 

Jump to main content.