Hundreds of uncontrolled forest fires blazed across Canada on Wednesday, threatening critical infrastructure, forcing evacuations and sending a blanket of smoky air wafting over cities in the United States.
Wildfires are common in Canada's western provinces, but this year flames have mushroomed rapidly in the country's east, making it the worst-ever start to the season.
About 3.8 million hectares have already burned, some 15 times the 10-year average, Federal Minister of Emergency Preparedness Bill Blair said.
"Across the country as of today, there are 414 wildfires burning, 239 of which are determined to be out of control," he told a briefing.
The giant eastern province of Quebec is among the worst affected.
"We've ... seen continued impacts to critical infrastructure in Quebec such as roads and rural closures, telecommunication interruptions and high voltage power lines being threatened by the growing fires," said Blair.
Quebec Premier Francois Legault earlier said the province was able to fight 40 fires at the same time.
"But we have 150 fires so we have to make sure that we focus where the problems are the more urgent," he told reporters.
South of the border, more than a dozen US states were under air-quality alerts on Wednesday as smoke from the wildfires wafted south.
An unusually early and intense start to wildfire season has set Canada on track for its worst-ever year of fire destruction as warm and dry conditions are expected to persist for months.
"In coming years we will have to reflect seriously on how we can equip ourselves to deal with this new reality. We will be facing more and more extreme weather events that will cost us a lot more," Prime Minister Justin Trudeau told the briefing.
Residents of the towns of Chibougamau and Ouje-Bougoumou in northern Quebec received evacuation orders Tuesday night, becoming the latest group of people in the province to evacuate homes after thousands were forced out last week.
About 11,400 people have been evacuated so far from remote parts of northern Quebec and another 4000 will be evacuated soon, Legault said.
In neighbouring Ontario province, Canada's most populous, deteriorating air quality has been forecast this week in cities including Ottawa and Toronto due to smoke plumes.
US cities affected
Schools across the East Coast of the US cancelled outdoor activities, flights were halted and millions of Americans were urged to stay indoors on Wednesday as smoke from the wildfires drifted south, blanketing cities in a thick yellowish haze.
The US 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.
"It's critical that Americans experiencing dangerous air pollution, especially those with health conditions, listen to local authorities to protect themselves and their families," US President Joe Biden said on Twitter.
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 licence today, and it was cancelled."
New York Governor Kathy Hochul called the situation an "emergency crisis," noting that the air pollution index for parts of her state were eight times above normal. She said the foul air was likely to persist for days, and that "people need to prepare for this over the long haul."
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.
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.
