Ozone pollution in Portland, Gresham and other cities could reach unhealthy levels for sensitive groups Tuesday afternoon.

Here's why the Canadian wildfire smoke is returning to the state and what to know about the latest air quality advisory.

The Bay Area Air District has issued an air quality advisory in the region for Tuesday because of smoke from a wildfire in ...

The Oregon Department of Environmental Quality has issued an air quality advisory for the greater Portland region through ...

An air quality advisory has been issued in the Bay Area for Tuesday due to wildfire smoke drifting in from the Gifford Fire ...

An air quality advisory has been issued for the Bay Area amid concerns about wildfire smoke drifting into the region.

Bay Area residents may see hazy skies and smell smoke, but the air district does not expect pollutant levels to exceed ...

A statewide air quality advisory will continue for Wisconsin from noon on Thursday to noon on Friday (Aug. 1).

An air quality advisory is in effect for New York City as smoke from Canadian wildfires continues to impact the region’s air, ...

Los Angeles County issues an unhealthy air quality advisory due to the Canyon Wildfire, affecting areas near the I-5 corridor ...