US air quality map: Alert issued for Philadelphia, Pittsburgh after Canadian, Minnesota wildfires: Code Purple activated

The Pennsylvania Department of Environmental Protection issued a Code Purple air quality alert for the entire state due to smoke from Canadian and Minnesotan wildfires.

Code Purple advises avoiding prolonged or strenuous outdoor activities; children, elderly, and those with respiratory conditions should avoid outdoor activities entirely.

Smoke from over 100 wildfires in Ontario arrived in Butler County and covered Philadelphia by late morning on July 17, 2026, lingering until at least Saturday.

Pulmonologist Dr. Leah Lande warned that wildfire smoke contains harmful gases, ozone, and fine particulate matter that pose health risks.