Smoke from more than 1,000 wildfires burning throughout Western Canada is once again a cause for concern in the Northern United States.
The National Weather Service has issued air quality alerts for a large swath of the Upper Midwest and Great Lakes region, impacting millions of Americans from Minnesota to Ohio. Major U.S. cities like Chicago, Minneapolis and Detroit all rank in the top 10 most polluted cities worldwide, according to the air pollution tracker IQAir.
Residents there are being urged to limit time outside, particularly those with respiratory concerns or other health issues.
Climate change blamed for wildfire smoke impacting the US
The smoke from Canadian wildfires has been widespread, extending "Code Red" air quality alerts for multiple cities in the U.S.
"We encourage limited prolonged activity for those with chronic respiratory issues and recommend children, teens, seniors, people with heart or lung disease, and individuals who are pregnant avoid strenuous activities and limit their time outside," Chicago Mayor Brandon Johnson said on Twitter. "Residents can also take individual action to reduce pollution levels, like carpooling or using public transportation."
The Canadian Interagency Forest Fire Centre reported more than 1,000 active wildfires in the country as of Tuesday, two-thirds of which are listed as "out of control." A vast majority of those blazes are burning throughout British Columbia, with smoke drifting southwest into the Upper Midwest of the United States.
Canada is experiencing its worst wildfire season on record. Earlier this year, a number of outdoor events in the U.S. were canceled or postponed due to poor air quality from Canadian wildfire smoke.
The smoke is coupled with an intense heat wave that has blanketed much of the U.S. for weeks, with temperatures in many places reaching triple digits.