Millions of people across the Great Lakes, Northeast and Mid-Atlantic endured another day of unhealthy air Friday as smoke from uncontrolled wildfires continued to blanket much of the eastern United States.

The thick smoke shrouded the nation's capital in a gloomy, eerie haze and forced the Cleveland Guardians to postpone their Major League Baseball game against the Pittsburgh Pirates in Ohio.

Air quality alerts warning of hazardous conditions were expected to remain in effect through Saturday across a broad swath of the country, although weekend storms could bring temporary relief to some of the hardest-hit areas.

In Washington, D.C., resident Stewart Verdery climbed to his rooftop at sunrise expecting his usual view of the city's iconic landmarks. Instead, he found a darkened skyline with the monuments completely obscured by smoke.

"It's pretty crazy to wake up at sunrise and not see the sun when it's not even raining," he said by phone after posting a video of the surreal scene on X. "And it smells like somebody's having the world's largest cookout."

There may be pockets of relief at times, including this weekend, but the smoky conditions are not expected to disappear anytime soon because the fires continue to burn largely unchecked, said Bob Oravec, a lead forecaster at the National Weather Service in Maryland.

Wildfires are burning in Ontario, Canada, as well as in the Boundary Waters Canoe Area Wilderness in Minnesota, which U.S. officials have closed as firefighters work to contain the blazes.

"The source of the smoke is going to continue for certainly a week, probably," Oravec said. "It's just going to depend on which way the wind's blowing as to where the smoke is going to have the greatest impact."

On Friday, communities in Minnesota, Illinois and Michigan, including Detroit, again recorded some of the worst air quality in the world, according to IQAir, an air quality monitoring website.

Not far behind Detroit was Washington, D.C., where the smoke created eerie scenes. The Washington Monument, the Lincoln Memorial and other national landmarks were enveloped in an orange-hued haze for much of the day.

People, particularly those with heart or lung disease, older adults and children, were urged to limit or avoid spending time outdoors until air quality improved.

Long-term exposure to smoky conditions can worsen existing health problems and contribute to chronic and potentially deadly conditions, including respiratory illness, cardiovascular disease, neurological disorders and premature death, officials warned.

For Maria Travela, Friday was her first day outside since wildfire smoke blanketed the Chicago area early Thursday.

"Now it's better. This morning, it was bad," said Travela, who has asthma and wore a mask as she crossed a bridge over the Chicago River downtown. "They were saying that, for people like me, with asthma, any kind of issues like that, it would be bad for your lungs."

Hundreds of wildfires are burning across Canada, including about 190 in northern Ontario, Premier Doug Ford said at a news conference. Flames destroyed the Namaygoosisagagun First Nation community, and 10 northern Ontario communities have been evacuated or were being evacuated, with more evacuations possible.

The increase in wildfires across Canada's vast forests has largely been attributed to climate change.

In response to the smoke, U.S. President Donald Trump posted on social media Friday blaming Canada for its forest management and threatening additional tariffs on the country.

The Canadian government did not immediately respond to questions about Trump's comments.

Asked about criticism from a Michigan lawmaker over the smoke, Ford noted that Canada has helped the United States fight wildfires in the past.

"If there's some politicians out there chirping away, maybe what you should do rather than complain is send support, send help, because we have done the exact same thing for our American friends and that's what you're supposed to do," Ford said.

In the New York City area, there was also concern about how the smoky air might affect Sunday's World Cup final between Spain and Argentina at MetLife Stadium in New Jersey.

Oravec said winds will continue pushing the wildfire smoke east across the United States, though conditions should improve by game day compared with Saturday.

On Thursday, a thick haze tinged with orange and yellow darkened skies across several states and partly obscured Manhattan's skyline.

Officials in New York, New Jersey, Pennsylvania and other Northeastern states distributed free KN95 masks, canceled outdoor activities and opened libraries and other public buildings as cooling centers where people could find relief from the smoky air.

As Friday progressed, air quality improved from "unhealthy" to "moderate" in some areas in and around New York City. Bright sunshine broke through a thin veil of smoke, and blue skies returned across much of the region by Friday afternoon.

Forecasters said thunderstorms were likely Saturday across much of the Northeast and Mid-Atlantic, helping improve air quality.

Organizers of the All-American Soap Box Derby in Ohio hoped air quality would improve enough to allow Saturday's championship races to proceed. The annual competition in Akron canceled Friday's events because of poor air quality.

"I think they made the right choice," said Dayna Lincoln, a pediatric nurse practitioner from Hodgdon, Maine, whose family drove 15 hours for their 9-year-old daughter's race Saturday.

"I'm glad they're not forcing the kids out into it," she said. "There are kids with asthma and adults with respiratory conditions who could really suffer."