Change Location:  
Number of Unhealthy Days Each Year (combined ozone and PM) Historical air quality trends
Number of Unhealthy Days Each Year For Ozone Historical air quality trends
Number of Unhealthy Days Each Year For PM2.5 Historical air quality trends

EPA Releases New Ozone Standard

Note: Data are preliminary and subject to validation
AQI Conversion Charts:
Ozone  Particulate Matter (PM)