What are "Code Red" and "Code Purple" air quality alerts? The Air Quality Index has six color-coded categories, ranging from cleanest to hazardous.

The Pennsylvania DEP has declared a statewide Code Purple Air Quality Alert for Friday, July 17. Wildfire smoke from Canada and Minnesota will cause unhealthy air across the state. Residents are urged ...

Air quality alerts can change quickly during wildfire smoke events. Here’s what Code Orange and Code Red mean, who is most at risk and when you should limit time outside.

A "Code Purple" alert is the second-highest level of the Air Quality Index and signifies a "very unhealthy" level of air pollution.