Topline
Raging wildfires burning in Canada and Minnesota have sent thick smog and smoke into the northern U.S. and put millions of people under air quality alerts, according to the National Weather Service, which warns more major cities in the Northeast and Mid-Atlantic are likely to be impacted in the coming days.
Smoke from Canadian wildfires as seen from Jersey City, New Jersey on July 15, 2026.
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Key Facts
Roughly 850 wildfires are burning in Canada, many of the largest in Ontario, and more than a dozen are ablaze in northern Minnesota as of Wednesday, coinciding with an extreme heat spell impacting much of the U.S.
A low pressure system making its way through southeast Canada has pushed smoke into the Lower 48, which is expected to result in orange sunrises and sunsets, fully-white or orange skies and air smelling like campfire smoke.
The Minnesota Pollution Control Agency’s West Duluth air quality monitor measured a new state record for wildfire smoke concentration Wednesday morning, and other major cities under dense and dangerous levels of smoke include Green Bay, Wisconsin; Detroit; Cleveland and Columbus, Ohio; and Buffalo and Rochester, New York.
Photos from Rochester show the air covered in thick, orange smoke, while some events in the Twin Cities have been canceled to encourage people to remain inside.
The NWS has issued air quality alerts for parts of Minnesota, Michigan, Wisconsin, Illinois, Indiana, Ohio, New York, Connecticut and Massachusetts, and fire weather watches in Washington state and northern Minnesota.
CRUCIAL QUOTE
“Folks – remember in 2023 when parts of the Northeast saw the skies turn orange? That may happen again,” meteorologist Matthew Cappucci warned in a tweet. “It may be time to break out the N95 masks – you don’t want to breathe in all these microscopic aerosols and particulates.”
What to watch for
How far the smoke spreads. It’s expected to filter further into the Northeast, Mid-Atlantic and Midwest through Friday and could reach New York City, Philadelphia, Baltimore, Washington, D.C., and Boston by Thursday morning.
BIG NUMBER
130,000 acres. That’s the size of the largest out-of-control wildfire in western Ontario, on the northern shores of Lake Superior, pushing smoke into the United States.
KEY BACKGROUND
Canadian wildfire smoke has affected the U.S. for decades, but the scale and frequency of major smoke events have increased in recent years. Hotter, drier conditions in Canada have contributed to larger and more intense wildfire seasons and, in 2023, smoke from record-breaking Canadian wildfires blanketed much of the eastern and central U.S. Those fires brought hazardous air quality from the Midwest to the East Coast and caused New York City to briefly record some of the worst air pollution in the world. Scientists say climate change has increased the likelihood of extreme fire weather in Canada and, when weather patterns permit, smoke can be carried deep into the U.S. Wildfire smoke is composed of water vapor, pollutants and particulate matter, which can penetrate the lungs and bloodstream. The smoke has been linked to respiratory and cardiovascular health problems, with children and teenagers, older adults, pregnant people and anyone with pre-existing heart or lung conditions at a particular risk.