Smoke from hundreds of wildfires burning in western Canada and the US moved across the Upper Mississippi Valley in the United States on Thursday, August 16.

Nearly 600 wildfires were burning in British Columbia, with dozens more in Alberta, Saskatchewan, and Manitoba, along with dozens more in the northwestern United States. Smoke from those fires was already following weather patterns across Manitoba and dipping into Montana, Wyoming, and North Dakota, and by Thursday, Minnesota was also seeing the haze.

A long strand of smoke has crossed Ontario as well, reaching to the Hudson Bay. Credit: NOAA via Storyful