The advisories impact large areas of Idaho, Oregon, Montana and Washington, lasting through the end of January.

The Air Quality Index measured 156 near Forks, Washington, and received a rating of "unhealthy," meaning some members of the ...

This measure, based on data from the Environmental Protection Agency, evaluates states on the number of days the Air Quality Index in counties was not rated “good.” U.S. News calculated a ...

The EPA measures regional air quality index (AQI) by how hazardous it is to the general public. Discover the AQI in your city by searching below.

As fires rage across the West Coast, destroying homes and forcing evacuations, the air we breathe has been severely impacted. In the following California air quality map, you can see how the air ...

Dust and ash left behind from the wildfires across Southern California can be irritating and hazardous when inhaled.

As wind and fire conditions change rapidly, zoom in and out on the interactive map below to see where air quality is worst around Southern California. You can also open the map in a new window here.

Despite Tuesday’s green map from the South Coast Air Quality Management District, showing air quality in Los Angeles County ...

The air and water quality subcategory informs the best states for natural environment rankings and the overall Best States rankings. It comprises two measures: the number of days with an air ...