As of Aug. 6, there are about 750 active Canadian wildfires, with at least 190 labeled “out of control,” according to the Canadian Interagency Forest Fire Centre. More than 16 million acres (6.8 million hectares) of land have been scorched this year, making this one of Canada’s worst wildfire seasons on record.

Smoke from Canadian wildfires is causing air quality concerns for millions of Americans in the Midwest and Northeast.  Air quality alerts were in effect Tuesday in several states, including Michigan and New York.

Red flag warnings remain in place for parts of Nevada, Utah, Colorado and Wyoming due to very dry conditions, low humidity and gusty winds.