1 of 5 | A view of the Kennedy Center and the Washington Monument covered in haze and smoke Thursday as a result of wildfires in Canada. Photo by Jemal Countess/UPI | License Photo
June 8 (UPI) -- Dangerous air conditions persisted into Thursday evening in Philadelphia, Baltimore, and Washington, D.C., canceling baseball games and forcing people indoors, with more smoke and haze expected through tomorrow.
For much of the day, U.S. agencies warned people across the Northeast to avoid inhaling smoke from Canadian wildfires, which clouded the air for the third day in a row Thursday and disrupted travel.
After primarily affecting the Northeast on Wednesday, the smoke reached parts of the Midwest and Southeast on Thursday.
More than 400 fires are burning in Canada, with the worst of the flames in the eastern provinces of Ontario and Quebec.
The thickest smoke is expected to spread over the Mid-Atlantic through Thursday night.
Dangerous levels of smoke and haze will be covering the Chesapeake Bay and Pittsburgh, Pa.
Major League Baseball rescheduled Thursday's game between the Arizona Diamondbacks and the Washington Nationals at the Nationals Park in Washington, D.C.
Two MLB games were postponed on Wednesday.
The U.S. Department of Energy and Environment in Washington issued an air quality warning and advised people in affected areas to stay indoors Thursday.
"Today the air quality is extremely unhealthy. Members of the general public may experience health effects and sensitive groups may experience more serious health issues. Some potential effects are heart attacks, irregular heartbeat, aggravated asthma, and decreased lung function," the DOEE tweeted Thursday.
"Everyone should stay indoors as much as possible, especially sensitive groups such as children, elderly, pregnant women and people with heart and lung conditions like asthma and bronchitis," the department said.
In New York, Gov. Kathy Hochul announced plans to provide about 1 million N95 masks to residents, "as smoke and haze as a result of ongoing Canadian wildfires continue to impact air quality throughout the state."
Air quality alerts were issued in at least 20 states, from Massachusetts south to Missouri and more than 75 million Americans are under air quality alerts.
The Federal Aviation Administration paused flights from multiple airports due to the smoke.
"Reduced visibility from wildfire smoke will continue to impact air travel today. We will likely need to take steps to manage the flow of traffic safely into New York City, D.C., Philadelphia and Charlotte," N.C., the FAA tweeted.
Later in the day, the FAA briefly grounded flights to Philadelphia due to low visibility.
Some New York events were also canceled due to the smoke, including three Broadway shows and the Chris Stapleton concert. New York schools announced Friday classes would be held remotely.
In the Washington area, Thursday's baseball game between the Washington Nationals and the Arizona Diamondbacks was postponed. The White House postponed a Pride Month event until Saturday.
Canada's Minister of Emergency Preparedness Bill Blair said the fires have burned about 9.4 million acres of forest, forcing the evacuation of at least 26,000 people.
President Joe Biden and Hochul, along with officials in New Hampshire and Maine, are sending firefighters to Canada to help fight the blaze.
AccuWeather senior meteorologist Brett Anderson said Quebec and Nova Scotia have set new seasonal records for the amount of land burned during a wildfire season.
"For Canada, the amount of acres burned through early June has already surpassed the 10-year average for an entire season," he said. "We are not necessarily seeing more fires with climate change, but larger fires that are consuming vast amounts of area."
AccuWeather contributed to this report.