The thick, hazardous haze that's disrupting daily life for millions of people across the U.S. and Canada, blotting out skylines and turning skies orange, should persist well into Thursday and possibly the weekend, experts say.

Weather systems are hardly expected to budge, so the smoky blanket billowing from wildfires in Quebec and Nova Scotia that are sending plumes of fine particulate matter as far away as North Carolina is expected to continue presenting challenges.

That means at least another day, or more, of the dystopian-style detour that's chased players from ballfields, actors from Broadway stages, delayed thousands of flights and sparked a resurgence in mask wearing and remote work - all while raising concerns about the health effects of prolonged exposure to such bad air.

The weather system that's driving the great Canadian-American smoke out - a low-pressure system over Maine and Nova Scotia - "will probably be hanging around at least for the next few days," U.S. National Weather Service meteorologist Bryan Ramsey said.

"Conditions are likely to remain unhealthy, at least until the wind direction changes or the fires get put out," Ramsey said. "Since the fires are raging - they're really large - they're probably going to continue for weeks. But it's really just going be all about the wind shift."

CBS Boston Chief Meteorologist Eric Fisher notes that, "It is really early. In Canada, they've already burned more acres than they usually burn through an entire season through November, and their wildfire season usually gets going in July, which says we are probably just going to be seeing a lot more smoke ... and we aren't just dealing with Canada smoke, we get it in the western United States, too." 

Dr. Nidhi Kumar, a cardiovascular specialist and a CBS New York contributor, said breathing the air where quality is worst "is probably way worse than smoking a cigarette. ... What we are dealing with right now are high levels of pollutants, toxins, carbon monoxide, and there's such a high concentration of it in the atmosphere right now, and that's causing not only cardiac issues for patients, [but also] pulmonary issues and just general inflammation in the body."

"These particles are really, really small, less than 2.5 micrometers. So what that means is that whenever we take a breath in, those particles are going straight into our lungs, deep into our lungs, and our bloodstream, and what that translates to is irritation and inflammation," Kumar explained.

Across the eastern U.S., officials warned residents to stay inside and limit or avoid outdoor activities again Thursday, extending "Code Red" air quality alerts in some places for a third-straight day as forecasts showed winds continuing to push smoke-filled air south.

CBS Baltimore said early Thursday that, "Todays air quality will be far worse than yesterday as the bulk of smoke from the Eastern Canada wildfires is pushed into the Mid-Atlantic. The pictures we saw from New York City yesterday could easily be our view today."

The station says many Maryland school districts cancelled after-school activities for Thursday.

In Washington, D.C., Mayor Muriel Bowser ordered schools to cancel outdoor recess, sports and field trips Thursday. In suburban Philadelphia, officials set up an emergency shelter so people living outside can take refuge from the haze.

New York Gov. Kathy Hochul said the state was making a million N95 masks - the kind prevalent at the height of the COVID-19 pandemic - available at state facilities, including 400,000 in New York City. She also urged residents to stay put.

"You don't need to go out and take a walk. You don't need to push the baby in the stroller," Hochul said Wednesday night. "This is not a safe time to do that."

New York City Mayor Eric Adams said, "This is an unprecedented event in our city, and New Yorkers must take precautions." He distributed masks to some city residents.

The message may be getting through. Officials said Wednesday the city hadn't seen an uptick in 911 calls related to respiratory issues and cardiac arrests.

More than 400 blazes burning across Canada have left 20,000 people displaced. The U.S. has sent more than 600 firefighters and equipment to Canada. Other countries are also helping.

Canadian Prime Minister Justin Trudeau spoke to President Biden by phone on Wednesday. Trudeau's office said he thanked Mr. Biden for his support and that both leaders "acknowledged the need to work together to address the devastating impacts of climate change."

Canadian officials say this is shaping up to be the country's worst wildfire season ever. It started early on drier-than-usual ground and accelerated quickly. Smoke from the blazes has been lapping into the U.S. since last month but intensified with recent fires in Quebec, where about 100 were considered out of control Wednesday.

"I can taste the air," Dr. Ken Strumpf said in a Facebook post from Syracuse, New York, where the sky took on the colorful nickname of the local university: Orange.

The smoke was so thick in Canada's capital, Ottawa, that office towers just across the Ottawa River were barely visible. In Toronto, Yili Ma said her hiking group canceled a planned hike this week, and she was forgoing the restaurant patios that are a beloved summer tradition in a nation known for hard winters.

"I put my mask away for over a year, and now I'm putting on my mask (again)," Ma lamented.

Eastern Quebec got some rain Wednesday, but Montreal-based Environment Canada meteorologist Simon Legault said no significant rain is expected for days in the remote areas of central Quebec where the wildfires are more intense.

The Federal Aviation Administration tweeted Thursday morning that, "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, DC, Philadelphia and Charlotte."

Major League Baseball's New York Yankees and Philadelphia Phillies postponed games.

On Broadway, "Hamilton" and "Camelot" canceled Wednesday performances and "Prima Facie" star Jodie Comer left a matinee after 10 minutes because of difficulty breathing. The show restarted with an understudy, show publicists said.

It wasn't to be at Central Park's outdoor stage, either. Shakespeare in the Park canceled its Thursday and Friday performances of "Hamlet."

In:
• Air Pollution
• Air Quality
• Wildfire
• East Coast
• Wildfire Smoke
• Canada