Wildfire Smoke Blots Sun and Prompts Health Alerts in Much of U.S.

An eye-watering and cough-inducing smoky haze from Canadian wildfires smothered a swath of the eastern and northern United States on Tuesday, with officials warning residents with health risks to stay indoors and keep their windows closed.

Health alerts were issued from New York to the Carolinas, and as far west as Minnesota. In New York City, the smoke could be tasted as well as smelled, and it wrapped the Statue of Liberty, the Empire State Building and Manhattan’s other landmarks in a blanket of orange-gray haze.

IQAir, a technology company that tracks air quality and pollution, said New York’s air quality was among the worst in the world on Tuesday night; the city usually does not rank in the top 3,000. One fan at the game between the Yankees and the Chicago White Sox being played in the Bronx likened the experience to being inside “one of those old-school Weber grills,” although the game continued without interruption.

The smoke was pouring across the border from Canada, where hundreds of wildfires remain unchecked, and the hazardous smoke conditions are expected to linger through Wednesday and perhaps until later in the week.

“It’s going to be here for a while,” said Bryan Ramsey, a National Weather Service meteorologist in New York. It is possible that conditions could ease on Wednesday, he said, before another blanket of smoke descends on the East Coast in the afternoon.

In North Carolina, the state’s Department of Environmental Quality said the state would be under Code Red or Code Orange air quality alerts through Wednesday because of the “rapidly rising levels of fine particle pollution attributed to smoke” from the wildfires. Officials are urging residents, particularly those with asthma, to stay indoors as much as possible.

In satellite images, the smoke appeared to be particularly thick over portions of Quebec, Ontario and New York.

The worst effects were in Canada, where more than 400 active wildfires were burning, according to the Canadian Interagency Forest Fire Center, exacerbating an already active wildfire season that is expected only to worsen. More than 200 of the fires, many of them in Quebec, were burning out of control, the agency said. Toronto briefly ranked among the worst 10 cities in air quality on Tuesday.

An estimated 26,000 people across Canada had been evacuated as of Monday, Bill Blair, Canada’s minister of public safety, said at the news conference.

“The images that we have seen so far this season are some of the most severe ever witnessed in Canada,” Mr. Blair said.

Hundreds of soldiers were deployed across Canada to help with firefighting efforts. Many Canadians who had to evacuate in recent days had just a few hours to pack before fleeing their homes, Prime Minister Justin Trudeau said at the news conference.

“This is a scary time for a lot of people,” Mr. Trudeau said.

Mr. Trudeau said on Monday that forecasts indicated that “this may be an especially severe wildfire season throughout the summer.”

There have already been more than 2,200 wildfires in Canada this year, according to the country’s fire agency.

Though it is difficult to link any particular fire outbreak to climate change, a landmark United Nations report concluded last year that the risk of devastating wildfires around the world would surge in coming decades as climate change further intensified what the report called a “global wildfire crisis.”

As the air-quality crisis continues, older adults, children and people with heart or lung conditions, including asthma, will be especially at risk, officials warned.

The New York Road Runners, the organization that owns and stages the New York City Marathon, urged runners living in areas polluted by the smoke to consider not running on Global Running Day on Wednesday. Jennifer Stowell, a postdoctoral fellow at Boston University School of Public Health, who has studied the health effects of wildfires, told The New York Times in 2020 that wildfire smoke “may be more toxic” to the lungs than standard urban air pollution.

In Oswego, N.Y., on Lake Ontario, the smoke created a haze that settled over the city on Tuesday and gave the sky a yellowish tint most of the day. By evening, a steady breeze had picked up, but the smell of smoke was still detectable and the streets were mostly empty.

School districts in Oswego County canceled athletic events and outdoor after-school activities. The Oswego Little League said it was canceling all of its games out of an abundance of caution. Even a planned D-Day ceremony in the nearby city of Fulton to honor a soldier who received the Medal of Honor for his actions on June 6, 1944, was postponed.

Though the Yankees played on, their top minor league team canceled a home game in Moosic, Pa.

In Manhattan on Tuesday evening, some commuters were startled by smell.

At the subway station at West 86th Street and Broadway around 6:45 p.m., passengers trudged up the stairs and onto the street and gasped. The sky was a strange orange-gray, and the cool air smelled of smoke.

“This morning, it smelled like burnt toast, but now it’s more like campfire,” said Benjamin Lukas, 47, who was on his way to his mother’s apartment to cook her dinner. “It’s just wild.”

Mr. Lukas worried about his mother’s breathing — and hoped that she had her windows shut, despite the cost of air-conditioning.

For some New Yorkers, the news of the Canadian wildfires came as a surprise, even as they breathed in the smoky air. “That’s what this is?” asked Joe Lerner, as he waited for a crosstown bus. “I figured it was a building fire or something.” Already, he said, his throat felt a little sore.

Covid masks were suddenly in demand. On her way home from work on the Upper West Side of Manhattan, Genevieve Cruz was making a quick stop into the CVS on Amsterdam Avenue, hoping the pharmacy was still selling masks.

“I used to have one on me all the time for Covid,” she said. “I can’t believe I don’t even have a single one anymore.”

Reporting was contributed by Kate Lowenstein, Ben Shpigel, Steve Kenny, Eduardo Medina, Scott Dodd, Jennie Coughlin, Felice Belman, Ashwin Seshagiri, Mary Suh, Ernesto Londoño, Ed Shanahan and Vjosa Isai