National Maps
AQI Legend
Air Quality Index Scale
0 - 50
Good
51 - 100
Moderate
101 - 150
Unhealthy for Sensitive Groups (USG)
151 - 200
Unhealthy
201 - 300
Very Unhealthy
301 +
Hazardous
Highest NowCast AQI Locations
This is a list of Reporting Areas with the highest current Air Quality Index (AQI) values. Ozone and particle pollution monitors across the country report current air quality readings to AirNow around the clock. The AirNow system generates a list of where the AQI for ozone or particle pollution is currently the highest at any given hour; this list automatically updates hourly, so the list changes several times day.
Air Quality Index Scale
0 - 50
Good
51 - 100
Moderate
101 - 150
Unhealthy for Sensitive Groups (USG)
151 - 200
Unhealthy
201 - 300
Very Unhealthy
301 - 500
Hazardous
Values above 500 are beyond the AQI scale
