NEW YORK (AP) — Smoke from Canadian wildfires poured into the US East Coast and Midwest on Wednesday, covering the capitals of both nations in an unhealthy haze, holding up flights at major airports and prompting people to fish out pandemic-era face masks.

While Canadian officials asked other countries for help fighting more than 400 blazes nationwide that already have displaced 20,000 people, air quality with what the US rates as hazardous levels of pollution extended into central New York. Massive tongues of unhealthy air extended as far as Virginia and Indiana, affecting millions of people.

“I can taste the air,” Dr Ken Strumpf said in a Facebook post from Syracuse, New York, which was enveloped in an amber pall. The smoke, he later said by phone, even made him a bit dizzy.

In Baltimore, where officials warned residents to stay indoors when possible, Debbie Funk sported a blue surgical mask as she and husband, Jack Hughes, took their daily walk around Fort McHenry, a national monument overlooking the Patapsco River. The air hung thick over the water, obscuring the horizon as distant ships pushed slowly through the haze.

“I walked outside this morning and it was like a waft of smoke,” said Funk, who said the couple had considered skipping the walk but wanted some exercise. The two planned to stay inside later Wednesday.

Canadian officials say this is shaping up to be the nation’s worst wildfire season ever. It started early on drier-than-usual ground and accelerated very quickly, exhausting firefighting resources across the country, fire and environmental officials said.

Smoke from the blazes in various parts of the country has been lapping into the US since last month but intensified with a recent spate of fires in Quebec, where more than 100 were burning and considered out of control Tuesday.

“The smoke was insane yesterday. I had to close my window because the fresh air just smelled like campfire,” said Zachary Kamel, 36, of Montreal.

Quebec Premier François Legault has said the province has the capacity to fight about 40 fires at the moment — and the usual reinforcements from other provinces have been strained by fires in Nova Scotia and elsewhere.

“There are a lot of fires that have been not been fought,” Legault said.

Canadian Interagency Forest Fire Centre spokesperson Jennifer Kamau said more than 950 firefighters and other personnel have already arrived from the US, Australia, New Zealand and South Africa, and more will be arriving soon.

The largest town in Northern Quebec — Chibougamau, population about 7,500 — was evacuated Tuesday, after another Quebec community was left to burn Monday, drawing the ire of local residents. Legault said authorities had no choice because the fire around the hamlet of Clova was too intense to send in water bombers. No homes had burned as of Tuesday.

Eastern Quebec got some rain Wednesday, but none is expected for days in the remote areas of central Quebec where the wildfires are more intense, Legault said.

US National Weather Service meteorologist Zach Taylor said the current weather pattern in the central and eastern US is essentially funneling in the smoke. Some rain should help clear the air somewhat in the Northeast and Mid-Atlantic this weekend or early next week, though more thorough relief will come from containing or extinguishing the fires, he noted.

Across the border, New York Govorner Kathy Hochul warned the public to “prepare for this over the long haul,” New York City Mayor Eric Adams told residents to limit outdoor activities as much as possible.

The Federal Aviation Administration temporarily held up flights at LaGuardia and Newark airports for weather and low visibility and said smoke was contributing to delayed arrivals at Dulles International Airport outside Washington.

Schools in multiple states cancelled sports and other outdoor activities, shifting recess and lunch time inside. Live horse racing was cancelled Wednesday and Thursday at Delaware Park Wilmington. Organisers of Global Running Day, a virtual 5K and celebration of running, posted a warning on their website advising participants to monitor the air quality in their cities and change their running plans accordingly.