Concern for poor air quality in the greater Chicago area remains as the Illinois EPA extends its alert until Thursday night. The city also is expected to get slightly warmer each day until the weekend.

Good afternoon, Chicago. Air quality alerts issued today in Illinois because of Canadian wildfire smoke marked the latest bout in an increasingly common summer occurrence. The alert covers 34 Illinois counties designated as having unhealthy air for all residents.

Smoke from ongoing wildfires across Canada continued to drift into parts of the United States on Wednesday, causing hazy skies and triggering air quality alerts in multiple states across the upper Midwest and Northeast.