The Chicago area recorded ozone levels of 156 late Monday afternoon. Levels above 100 are considered unhealthy. Residents ...

The Illinois Environmental Protection Agency has issued an Air Pollution Action Day for Tuesday, July 15. Here's what to know ...

Additional plumes of smoke from Canada's active wildfires prompt officials to issue a statewide air quality alert on July 14.

An air quality alert for northwest Minnesota has been extended to cover the entire state and run through Monday.

When air quality is ranked "unhealthy for vulnerable groups" it means PM 2.5 are at levels that can cause problems for people ...

With wildfire smoke in the forecast, track the drop in air quality across dozens of PurpleAir sensors with our live, updating ...

The Air Quality Index (AQI) is a national system developed by the U.S. Environmental Protection Agency (EPA) to translate various air pollutant concentrations into a single, easy-to-understand number.

Wildfire season is upon us once again, and smoke is reducing air quality through swaths of the country. Environment Canada ...

Canadian wildfire smoke lingers in Michigan. Officials issued an air quality advisory in southeast Michigan for July 15.

Wildfire season is upon us, and smoke is reducing air quality through swaths of the country. Environment Canada suggests ...

An Air Quality Alert has been issued for parts of northern New York and Vermont today because of Canadian wildfire smoke.

The DEC has issued an air quality health advisory for most of upstate New York due to elevated levels of fine particulate ...