Wildfires across North America cause hazardous air quality for millions.

Dangerous air quality caused by smoke from Canadian wildfires will impact millions of Americans in the Midwest and Northeast early this week. Dry weather and gusty winds have increased the wildfire risk in the region, with a large portion of Michigan under a red flag warning. The smoke will intensify by Tuesday morning, impacting areas from Nashville to New York City. Older adults, kids, people with lung or heart disease, and pregnant women should avoid heavy exertion. Tropical Storm Arlene has fizzled out, but south Florida remains under a flood watch due to heavy rain.