Hundreds of wildfires in Canada have sent thick clouds of hazardous smoke across large parts of the United States, covering the Midwest and Northeast with dangerous air pollution. Authorities have urged millions of residents to stay indoors as air quality continues to deteriorate across several states.
According to air quality monitoring data, Detroit recorded the worst air pollution level of any major city in the world on Thursday, with an Air Quality Index reaching 600, double the level classified as hazardous by the US Environmental Protection Agency (EPA). Dangerous smoke conditions were also reported across Minnesota, Michigan, Illinois, Ohio, Ontario, and several other regions, while at least 10 US states recorded unhealthy air quality.
Experts described the smoke as a massive “river of smoke” flowing from Canada into the United States. Atmospheric chemist Emily Fischer said the event highlights the growing impact of climate change, explaining that increasing temperatures are contributing to more frequent and intense wildfire seasons.
The poor air quality forced the cancellation of concerts, sporting events, outdoor camps, and recreational activities across Minnesota. Public parks, golf courses, swimming pools, and other outdoor facilities were also temporarily closed to protect public health.
In New York City, smoke covered the skyline with a visible orange haze, while residents reported a strong burning smell in the air. City officials advised everyone to reduce outdoor activities, particularly older adults, pregnant women, children, and people with heart or lung conditions. The city also distributed free KN95 face masks through libraries, police stations, and firehouses.
The hazardous conditions come just days before the FIFA World Cup Final in nearby New Jersey, raising concerns about air quality for players, spectators, and event staff.
Canadian officials reported 858 active wildfires, with 111 fires still out of control. More than 5.9 million acres have already burned during this year’s wildfire season. Scientists warn that wildfire smoke can travel thousands of miles and is significantly more harmful than normal air pollution, increasing the risk of heart disease, stroke, respiratory illness, and other serious health conditions.
