According to the National Weather Service, the air quality alert remains in effect through midnight in parts of the Chicago area, including Kane, DuPage, Kendall, Grundy, Cook and Will counties.

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.

Wildfire smoke has pushed Chicago's air quality into the "unhealthy" zone. It's so bad, in fact, that we're the most polluted city in the world right now. Here's what you should know.