Smoke Comes & Goes & Comes Again: Here’s Why

Wildfire smoke in Niagara region, St. Catharines, ON, 15 July 2026 (photo from Wikimedia) 19 July 2026 As I wrote on Friday 17 July, wildfire smoke has been plaguing the northeastern U.S. and the Great Lakes region in the U.S. and Canada. The photo at top shows the worst day in the Niagara Falls area as seen in St. Catharines on Wednesday 15 July. Pittsburgh’s worst day was Friday the 17th, shown in the video below. Wildfire smoke in Pittsburgh on 17 July 2026, video embedded from WTAE-TV Pittsburgh on YouTube The source is nearly 1,000 forest fires in northern Minnesota and western Ontario, most of them at least a 1,000 miles away. Across the continent there are many, many more. Here’s what’s burning in North America this morning according to NASA’s Fire Information for Resource Management System US/CANADA map. Wildfires in North America on 19 July 2026 (NASA FIRMS US/CANADA) On Friday Pittsburgh’s air was so bad it was Hazardous (Maroon color) … Air Quality color codes from…