Authorities say that Canadian wildfires are causing air pollution throughout the United States.
Wildfires raging in British Columbia have blanketed much of the U.S. Northwest with thick smoky haze.
The Air Quality Index says the air is considered unhealthy in some parts of western Washington, meaning everyone in the region could experience health issues from polluted air.
Hundreds of wildfires are burning across British Columbia, causing thousands to evacuate.