Most of the smoke is from fires in western Canada and the western United States ... that is bringing in a northwest flow to the state of Maine. Plumes of smoke are expected to impact the look ...

Wildfires, like this one in British Columbia's Tweedsmuir Provincial Park, continue to burn in Canada. Smoke from Canada's wildfires has again blanketed swathes of the US, leaving tens of millions ...

Major air pollutants have declined in recent decades, but USA TODAY’s analysis shows wildfire smoke is taking their place.