Updated July 18, 2026 at 4:12 PM CDT
WASHINGTON — Poor air quality persisted in the Northeast, Mid-Atlantic and Midwestern states on Saturday, as smoke from hundreds of wildfires burning in Minnesota and Canada continued to spread and envelop skylines. The National Weather Service (NWS) said heavy rain and storms could help clear the air in the northeast and mid-Atlantic this weekend, while dangerous levels of air pollution will still hang over the Midwest.
"As we start clearing out here in the east, they're going to get the next batch of smoke later this afternoon into tonight across areas from upper Michigan, eastern Wisconsin, into Illinois and Indiana, including Chicago," NWS Forecaster Brian Hurley told NPR. "That will continue through [Sunday], unfortunately."
Major League Baseball postponed Friday's game between the Pittsburgh Pirates and the Cleveland Guardians due to poor air quality in Cleveland until Saturday.
Hurley said conditions in the Washington, D.C., area are improving, following the eerie appearance of the city's landmarks enveloped in a thick, smoky haze on Friday. Air pollution will remain elevated into next week.
"But not nearly to the level that we've been seeing. We're only talking about maybe a fourth or a third of the concentration of particulates," he explained, adding the haze will have mostly faded away by Sunday.
Clearer air conditions are also expected in areas north of D.C. along the East Coast, including New York City and northern New Jersey, where Sunday's World Cup final between Argentina and Spain will be played at MetLife Stadium, an open-air venue.
More than 900 active wildfires are burning in Canada, including in the Manitoba and Ontario provinces bordering the northern U.S.
President Trump threatened to impose new tariffs on Ottawa in a post on Truth Social on Friday. He accused Canada of failing to maintain its forests and said the U.S. is being "invaded by filthy, polluted, and unhealthy air." Trump said he planned to call Prime Minister Mark Carney:
"This is Willful Negligence, and becoming a yearly occurrence, costing the United States Billions of Dollars, which cost of this pollution must of necessity be added to the TARIFFS Canada is currently paying," Trump's post read in part.
U.S. lawmakers blame Canadian officials
Four Republican members of the U.S. House of Representatives from Michigan sent a letter to Carney on Wednesday accusing the Canadian government of dismissing the health of Americans and asking what steps Ottawa has taken to reduce wildfire risk in provinces bordering midwest states. While speaking to reporters on Thursday, Carney responded that both countries share responsibility in fighting climate change.
The U.S. Forest Service reported that the Bear Trap Fire and the Thumb Fire burning in the Superior National Forest in Minnesota crossed the U.S. border into Canada earlier this week. The agency said earlier this month that aircraft was dropping water on the flames on the U.S. side and on Tuesday said it was coordinating with Canadian authorities. Ontario Premier Doug Ford noted during a press conference on Saturday that Canada has helped the U.S. fight many wildfires over the years.
Concerns about toxic smoke particles
Human-caused climate change has increased the risk of wildfires and intensified them.
Health experts are concerned about the effects on public health.
Peter DeCarlo, a professor in the Department of Environmental Health and Engineering at Johns Hopkins University, recommended using an air clearing device such as an air purifier to eliminate toxic air particles spread by the smoke.
"That's going to minimize the amount of particles that you would be breathing in that space," DeCarlo said.
He added: "The age of the home and how tight the building is adjusts how much of that particulate matter from outside smoke comes in. A rough estimate is on the order of 50% for a lot of the houses in the continental U.S."
DeCarlo also warned that children, pregnant women, older adults and people with pre-existing conditions face a particular risk of experiencing harmful impacts from poor air quality.
"N-95 masks are protective, not only from COVID particles, but also for pollution," said DeCarlo. "You can put on an N-95 and actually protect yourself pretty significantly with that if you want to go walk around the block and get some time outdoors."
The National Weather Service issued air quality alerts across New England on Saturday.
"A lot of these advisories or alerts are going to be through midnight. I think most areas are going to start to see improvement before that," said Hurley.
However, state and federal officials in Minnesota are warning fire conditions there remain volatile. MPR News reports more than 600 firefighters are battling wildfires in northeast Minnesota in extremely hot and dry conditions. The flames have burned through more than 70,000 acres, and are approaching residential and resort areas that were under evacuation orders on Saturday. Air quality levels in Minnesota have broken records in recent days, according to officials.
Thunderstorms, flooding and a possible risk of tornadoes are forecasted in the Mid-Atlantic, most of Pennsylvania and other areas of the Northeast this weekend.
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