Smoke from the raging wildfires in the U.S. Midwest drifted into southern Ontario on the current stretch of days. Environment Canada reported areas in Ontario among the worst globally for air quality in recent reports . Toronto faced urgent warnings about hazardous air from the unrelenting smoke . Extreme drought and fierce gusts helped fires spread at breakneck speed through Minnesota and nearby states. Harmful air drifted north, blanketing Canada in a thick veil of contaminants.