In the upper Midwest of the United States, Michigan, Wisconsin and Minnesota have issued air quality warnings as smoke from the Prairie wildfires is dragged south by a cold front. Those warnings expanded into the Northeast, causing some hazy skies.

A gray haze from wildfire smoke could be seen in Cincinnati, and the entire state of Minnesota is under an air quality alert.

Living in the Midwest means being affected by the Canadian wildfires that occur just about every year. Here is what to know about these wildfires and how they’re affecting the Midwest.

Many fires burning across Canada, forcing evacuations and threatening air quality in the United States, cannot simply be put out, authorities and experts say.

As the climate changes, the far north is drying and warming, which means wildfires are getting bigger and more intense. The area burned in Canada is now the second largest on record for this time of year,