Smoke from Canadian and Minnesota wildfires has pushed air quality to unhealthy and hazardous levels across the Midwest, Great Lakes and East Coast, while U.S. officials call for faster action and new accountability measures.
Heavy wildfire smoke from Canada and northern Minnesota has blanketed large parts of the United States, triggering air quality alerts from the Great Lakes to the East Coast and prompting health officials to urge residents to limit outdoor activity, use masks and stay indoors where possible.
Officials said smoke pushed air quality into unhealthy, very unhealthy or hazardous ranges in several areas, including Michigan, Minnesota, Chicago, New York City and Philadelphia. In Detroit, National Weather Service meteorologist Steven Freitag said a lingering high-pressure system trapped smoke close to the ground, reducing visibility in some locations to around half a mile.
Health officials warned that fine particles in wildfire smoke can travel deep into the lungs and enter the bloodstream, increasing risks for people with heart or lung conditions, older adults, children and outdoor workers. Long-term exposure has also been linked to chronic respiratory, cardiovascular and neurological health problems.
In New York City, agencies moved activities indoors, opened cooling centers and distributed masks at transit hubs and public locations after haze turned the sky orange and yellow and partly obscured the Manhattan skyline. Philadelphia officials advised residents to avoid strenuous outdoor activity and wear N95 or KN95 masks if they had to go outside.
The smoke comes as Canada’s wildfire season has rapidly exceeded historical norms. According to Canada’s National Wildland Fire Summary, the area burned rose from less than half the 10-year average on July 7 to 2.78 million hectares, or 6.87 million acres, by July 17. The total is already about 300,000 hectares above the 10-year average, while the number of fires has surpassed the 25-year average.
Fire danger remains extreme in Ontario, where evacuations have been ordered in multiple communities, and officials warned that hot, dry weather and lightning could fuel further growth. Wildfire smoke impacts are expected to continue in eastern Canada and across parts of the United States, particularly from fires in western Ontario.
In Minnesota, crews continued efforts to clear the Boundary Waters Canoe Area Wilderness along the U.S.-Canada border after officials closed the area. Authorities estimated that 6,000 to 10,000 people had been inside when the closure was issued, with most contacted by Superior National Forest staff. Smoke has hampered helicopter operations and officials said some fire may continue burning until fall or snowfall.
The air quality crisis has also prompted a political response in Washington. U.S. President Donald Trump and the Environmental Protection Agency urged Canadian officials to extinguish the fires as quickly as possible, while U.S. Sen. Bernie Moreno released legislation aimed at holding Canadian officials responsible for cross-border wildfire smoke.
Moreno’s proposed CANADA FIRE Act, scheduled for introduction in the Senate on July 20, would require the president to determine whether Canadian wildfire smoke harmed U.S. air quality and whether Canadian officials failed to respond adequately. If so, the bill would trigger sanctions, including restrictions on government contracts, visa revocations for officials found responsible and potential limits on imports or investment in Canadian state-owned entities.
Scientists and wildfire experts, however, have cautioned against framing the fires solely as a management failure. Researchers cited in reports said climate change has increased wildfire activity in both the United States and Canada by creating hotter, drier conditions and longer fire seasons. Canadian Prime Minister Mark Carney also said climate change is a shared responsibility and pointed to the need for clean energy investment.
Experts noted that smoke has crossed the border in both directions in recent years, including during major U.S. wildfires in the West. With active fires still burning across Canada and Minnesota, forecasters warned that smoky air could continue returning to affected communities depending on wind patterns until fires are fully contained or seasonal weather changes bring relief.
U.S. Sen. Bernie Moreno on Friday released text of legislation that would sanction Canadian government officials, block their assets and revoke their visas over wildfire smoke that has repeatedly fouled the air in Ohio and across the United States.
