As has been the case much of the summer, the smoke invasion is targeting the Upper Midwest to Great Lakes. Beyond Thursday, smoke may impact more of the Northeast U.S. through and beyond Friday.

A special air quality statement has been issued for Waterloo region and the surrounding area. And while it could improve, Environment Canada says to expect another round of bad air this weekend.

Wildfire smoke drifting across the Great Lakes has caused air quality to plunge to hazardous levels in several states, affecting millions of people in major cities.