The Midwest and Northeast registered some of the worst air quality in the world last week as wildfire smoke shrouded cities from Minneapolis to New York in an apocalyptic haze. More than 100 million Americans were under air-quality alerts, with smoke even reaching Washington, D.C., by the weekend.
Most of the smoke came from Canada, where about 900 wildfires were burning by Friday. Over 100 were burning in northwestern Ontario alone. Fires are also raging in northern Minnesota and across the western United States, where another brutal fire season is underway. Nearly 80 large fires are uncontained nationwide, and more than 3.9 million acres have burned this year.
