Before-and-after photos show just how quickly wildfire smoke has swallowed city skylines across parts of the U.S.
A persistent northwesterly wind is carrying smoke from nearly 80 out-of-control wildfires in Ontario, Canada, blanketing parts of the Northeast and Midwest in thick haze and unhealthy air.
Forecasters say the smoky conditions could stick around into Saturday before winds shift and help improve air quality.
President Trump says he’s holding Canada responsible for the air quality impacting Americans, adding that it’s costing the U.S. billions of dollars.