A large amount of smoke produced by Canadian wildfires drifted south into the United States on the night of the 15th, causing more than 115 million people in the Midwest and Northeast regions of the US to be threatened by unhealthy air quality. This situation is expected to persist until the 17th.
According to the US air quality monitoring website www.airnow.gov, the index of fine particulate matter (PM2.5) in the air in Chicago, Illinois has risen to 489, reaching a ‘hazardous’ level. In some areas of Michigan, the index reached as high as 500. Residents in some parts of both states said they could smell smoke even inside their homes.
The US National Weather Service has issued air quality alerts for affected areas. It is expected that the hazy conditions in the Midwest and Northeast areas will last until the evening of the 16th or possibly the 17th.
In recent days, wildfires sweeping through northwestern Ontario, Canada have caused the country's air quality to deteriorate sharply in many areas. In recent years, many regions of the United States have commonly experienced smoke haze from Canadian wildfires during the summer.