Air quality

A new study on air quality found that Los Angeles was the most polluted major U.S. city, while Seattle was the cleanest.

Ash from the recent LA County fires and burn scars formed by other wildfires in the fall can be dispersed by strong winds. See an air quality map.

The ongoing wildfires have put the Los Angeles area under an air quality alert, with the National Weather Service advising SoCal residents to remain indoors with their windows closed and wear N-95 masks if they have to go outside.

Check your air quality forecast in Washington, D.C., Maryland and Virginia, plus see safety tips.

Large wildfires have been burning for more than a week in Canada. News4’s Amelia Draper explains how the changing climate impacts these fires and why they are becoming more intense.

News4 Consumer Reporter Susan Hogan shares how humidifiers and air purifiers can help keep indoor air clean.