Widespread Air Quality and Extreme Heat Alerts Issued Across US Midwest and Northeast

Multiple regions across the U.S. Midwest and Northeast, including cities like Philadelphia and Chicago, are under Code Red Air Quality Alerts and Extreme Heat Health Alerts for July 16, 2026. These alerts are primarily due to smoke from Canadian wildfires and dangerously high temperatures, prompting health officials to advise residents, especially sensitive groups, to stay indoors, limit outdoor activities, and take precautions against heat-related illnesses.