Smoke from 858 wildfires burning in Canada transitioned across the U.S. Midwest and Northeast on Thursday, resulting in air quality alerts for at least 10 states. Data from the monitoring company IQAir reported that Detroit reached a pollution index of 600, a level twice the Environmental Protection Agency's threshold for "hazardous" air. High concentrations of smoke and "unhealthy" air readings were also noted in Minnesota, Michigan, Illinois, Ohio, and parts of Ontario.
Local officials, including New York City Mayor Zohran Mamdani, advised residents to limit outdoor activity and distribute KN95 masks to the public. Health experts cautioned that wildfire smoke presents risks for the elderly, pregnant women, and individuals with respiratory or cardiovascular conditions. The smoke arrives days before the FIFA World Cup final is scheduled to take place at MetLife Stadium in New Jersey on Sunday.
According to Canadian government data, approximately 5.9 million acres have burned during the current wildfire season. Of the 858 active fires, 111 are classified as out of control, with the majority located in Manitoba, Saskatchewan, and Ontario. Scientists from Colorado State University stated that the increasing frequency and intensity of such fires are linked to rising global temperatures, while atmospheric conditions have facilitated the movement of smoke across the border.