Haze and smoke shroud Manhattan skyline from Canadian wildfires in New York
People wear protective masks as the Roosevelt Island Tram crosses the East River while haze and smoke from the Canadian wildfires shroud the Manhattan skyline in the Queens Borough New York City, June 7, 2023. Reuters

Schools across the U.S. East Coast canceled outdoor activities, flights were halted and millions of Americans were urged to stay indoors on Wednesday as smoke from Canadian wildfires drifted south, blanketing cities in a thick yellowish haze.

The U.S. National Weather Service issued air quality alerts for virtually the entire Atlantic seaboard. Health officials in states from Vermont to South Carolina and as far west as Ohio and Kansas warned residents that spending time outdoors could cause health problems due to the amount of fine particulates in the atmosphere.

New York's world-famous skyline, usually visible for miles, appeared to vanish underneath the otherworldly veil of smoke, which some residents said made them feel unwell.

"I can't breathe. It makes breathing difficult," Mohammed Abass said as he walked down Broadway in Manhattan. "I've been scheduled for a road test for driving, for my driving license today, and it was canceled."

The reduced visibility caused by the haze forced the Federal Aviation Administration to slow or halt some flights into New York City at LaGuardia International Airport and Newark Liberty International Airport.

Schools up and down the East Coast called off outdoor activities, including sports practices, field trips and recesses, to protect students.

In Bethesda, Maryland, a high school moved its graduation ceremony indoors, while a Brooklyn, New York, elementary school postponed its "Spring Fling" dance party. A school in Montclair, New Jersey, called off a fifth-grade trip to a Six Flags amusement park.

In some areas, the Air Quality Index (AQI), which measures major pollutants including particulate matter produced by fires, was well above 400, according to Airnow, which sets 100 as "unhealthy" and 300 as "hazardous."

At 12 p.m. EDT (1600 GMT), Bethlehem, Pennsylvania, was experiencing the worst air-quality in the country, with an AQI reading of 410. Among major cities, New York had the worst air quality reading in the world on Wednesday afternoon at 342, about double the reading for chronically polluted cities such as Dubai (168) and Delhi (164), according to IQAir.

SMOKE CROSSING FROM CANADA

The smoke is crossing the U.S. northern border from Canada, where wildfire season got off to an unusually early and intense start due to persistent warm and dry conditions. Canada is on track for its worst-ever wildfire season.

The skies above New York and many other North American cities grew progressively hazier through Wednesday, with an eerie yellowish tinge filtering through the smoky canopy. The air smelled like burning wood.

Wildfire smoke has been linked with higher rates of heart attacks and strokes, increases in emergency room visits for asthma and other respiratory conditions, and eye irritation, itchy skin and rashes, among other problems.

A Home Depot in Manhattan sold out of air purifiers and masks as residents scrambled to protect themselves. New York Road Runners canceled events intended to mark Global Running Day.

"This is not the day to train for a marathon or to do an outside event with your children," New York Mayor Eric Adams advised. "If you are older or have heart or breathing problems or an older adult, you should remain inside."

City pedestrians donned face masks in numbers that recalled the worst days of the coronavirus pandemic.

Tyrone Sylvester, 66, was sitting outside playing chess in Manhattan's Union Square as he has done most days for 30 years.

He had a face mask on for the first time in a long time and said he had never seen air quality as bad in the city as it was on Wednesday.

"When the sun looks like that," he said, pointing to the bronze-like appearance of the star in the smoky sky, "we know something's wrong."

While wildfires are common in Canada's West, there are blazes across the country, especially in the eastern province of Quebec.

About 3.3 million hectares have already burned - some 13 times the 10-year average - and more than 120,000 people have been at least temporarily forced out of their homes.

Smoke from Canada wildfires blankets Washington, D.C.
People take photos at the Lincoln Memorial Reflecting Pool as smoke from wildfires in Canada blankets the National Mall in Washington, June 7, 2023. Reuters
Haze and smoke shrouds Manhattan skyline from Canadian wildfires in New York
A performer plays the violin as a passerby wears a mask in Times Square as Manhattan is shrouded in haze and smoke which drifted south from wildfires in Canada, in New York City, New York, June 7, 2023. Reuters
The Statue of Liberty is covered in haze and smoke caused by wildfires in Canada, in New York
The Statue of Liberty is covered in haze and smoke caused by wildfires in Canada, in New York, June 6, 2023. Reuters
A girl on a swing is seen in silhouette as haze and smoke from the Canadian wildfires shroud the sky at Barretto Point Park in the Bronx borough of New York City
A girl on a swing is seen in silhouette as haze and smoke from the Canadian wildfires shroud the sky at Barretto Point Park in the Bronx borough of New York City, June 7, 2023. Reuters
The Manhattan skyline is covered in haze and smoke caused by a wildfire in Canada, in New York
The Manhattan skyline is seen covered in haze and smoke, in New York, June 7, 2023. Reuters
Smoke from wildfires in Toronto
A smoky Toronto skyline is seen with a blanket of smoke from the CN Tower as wildfires in Ontario and Quebec continue to burn, in Toronto, Ontario, Canada June 6, 2023. Reuters