New York Mayor Eric Adams told residents they should stay inside or wear masks outdoors to battle the smoke from Canadian wildfires that is blanketing the largest US city and swaths of the East Coast.

The Federal Aviation Administration reported delays in New York, Philadelphia and Newark, New Jersey. Major League Baseball postponed the Yankees-White Sox game in New York and the Tigers-Phillies game in Philadelphia.

Canada is experiencing an unprecedented amount of pre-summer fire activity. More than 400 forest fires are still active across the country, and most of them are out of control. Prime Minister Justin Trudeau said Canada is living through its “worst wildfire season” in recorded history.

Key Stories:

• NYC Flights Delayed as Wildfire Smoke Blankets the Region
• Canada Wildfires Envelop Millions of North Americans in Smoke
• World’s Worst Air Cloaks New York City in Smoky Orange Haze
• Big Take: Wildfire Smoke Leaves Children Gasping for Air Years Later

Here’s the latest news: (All times are NY)

President Biden Speaks With Trudeau (10:10 p.m.)

President Joe Biden offered additional support to fight the wildfires burning in Canada during a call with Prime Minister Justin Trudeau, according to a readout of the conversation. The US has already deployed more than 600 firefighters and support personnel, and Biden directed his team to provide all available assets that can rapidly assist in suppressing the blazes.

Trudeau Says Climate Change to Blame (7:21 p.m.)

Trudeau made the comment after the call with President Biden. He added that hundreds of US firefighters have arrived in Canada, and more are on the way.

New York to Distribute N95 Masks (5:31 p.m)

Wildfires Burn in Canada’s Worst Season (4:30 p.m.)

Wildfires continue to burn large tracts of forest in Canada, with little sign weather will provide much help to firefighters who are battling the blazes that are sending smoke over New York and other major cities.

More than 400 forest fires are still active across the country, and most of them are out of control. Prime Minister Justin Trudeau said Canada is living through its “worst wildfire season” in recorded history during a briefing with journalists in Ottawa on Wednesday.

Wildfires are poised to burn more land than ever in Canada, with over 3.8 million hectares (9.4 million acres) scorched so far, according to the Canadian National Fire Database. That’s about double the size of New Jersey.

Jodie Comer Leaves Broadway Performance (4 p.m.)

Actress Jodie Comer left the stage of her one-woman Broadway show, “Prima Facie,” shortly after it started because she had trouble breathing, the New York Times reported. The matinee performance restarted with an understudy in her place.

Google Tells Employees to Work From Home (4 p.m.)

Google told its East Coast employees to work from home, CNBC reported, citing a memo. Advisory notices were sent to workers in Detroit; Washington, D.C.; Reston, Virginia; Pittsburgh and Raleigh-Durham, North Carolina. The company also issued the notice to workers in Toronto and Waterloo in Ontario, Canada

NYC Has Worst Air Among Major Cities (3:50 p.m)

Air quality in New York City remained at hazardous levels Wednesday afternoon, according to IQAir, a pollution mapping tool. Currently the city’s air ranges up to 355 on its 0 to 500 scale, meaning it has the worst air quality of any major city in the world, followed by Dubai at 167.

LaGuardia Reports Two-Hour Delays (3:39 p.m.)

As of 3:30 p.m. New York time, LaGuardia flights were operating with average delays of about two hours. Newark and Philadelphia airports were also on ground delays because of low visibility, with average delays of 82 minutes and 29 minutes, respectively, according to the FAA.

Thursday Smoke May Skirt NYC (3:35 p.m.)

New York is “getting the big peak now,” said Alex Lamers, a warning coordination meteorologist at the US Weather Prediction Center. The worst of the smoke, which has reached hazardous levels in many areas of the Northeast, will be blown down the Interstate 95 corridor through the night and could pass through Philadelphia, Baltimore and Washington.

On Thursday, another round of smoke will move into the US, but it may be to the west of New York City, settling across the Great Lakes and Ohio Valley, Lamers said. Where the smoke goes depends on how winds set up across the eastern US, but as long as a low pressure system remains stuck near Nova Scotia, the breezes will be blowing south, so New York isn’t “completely out of the woods” yet, Lamers said.

Flights to LaGuardia Grounded (1:43 p.m.)

The Federal Aviation Administration said inbound flights to LaGuardia Airport in New York City have been grounded due to low visibility as smoke from fires across eastern Canada blankets the city.

Departures to LaGuardia were grounded from 12:50 p.m. New York time and will stay grounded until at least 2 p.m., but the FAA said in a status update the probability of an extension was low — “less than 30%.”

Inbound flights to Newark Liberty International Airport in New Jersey were also delayed for more than an hour on Wednesday afternoon.

Smoky Blanket Spurs Health Concerns (1:02 p.m.)

Health officials across the US Northeast are warning residents to take precautions after wildfire smoke traveling south from Canada unleashed unhealthy air quality levels that pose a risk to the sick, elderly and young children.

New York City officials canceled outdoor school recess and suggested the most vulnerable wear high quality masks after a thick haze that blanketed skies triggered an overnight purple alert, the highest and most dangerous level. The health warning may last for at least another day, Mayor Eric Adams said in a press conference. Massachusetts, Maryland, Pennsylvania, New Jersey and Washington, DC, leaders also issued warnings.

NYC Will Choke on Smoke for Days (10:51 a.m.)

The US Northeast, including New York City, will continue to breathe in choking smoke from fires across eastern Canada for the next few days, raising health alarms across impacted areas.

While there could be showers in New York on Thursday, the smoke will likely linger, said John Cristantello, a National Weather Service meteorologist. “Rain can only do so much,” he said. “The bigger factor is the magnitude of the smoke and the wildfires.”

Air quality alerts stretch across Quebec and Ontario, including Montreal, Toronto and Ottawa, and from New York and New England to South Carolina in the US.

--With assistance from Elizabeth Elkin.