Canada’s wildfire plague widened on Friday, with Yellowknife’s 20,000 residents rushing to meet a deadline to evacuate, while blazes hundreds of miles away threatened Kelowna, a much larger city in British Columbia.
The mass migration from Yellowknife, the capital of the Northwest Territories, was the biggest mandatory evacuation so far in Canada’s summer of wildfire disasters.
By midday, it remained unclear how many of Yellowknife’s residents had heeded the order as an encroaching fire loomed, but parts of the city appeared empty and most stores appeared closed.
In Kelowna, a major resort area, homes on its suburban fringes were on fire and orders to evacuate were decreed in a community where several homes were destroyed on Thursday night and others were burning on Friday.
The blazes amplified Canada’s image as an epicenter of wildfires in a year of record heat around the world, which scientists widely attribute at least in part to climate change. Canada has reported a record number of wildfires this year, with more than 5,700 burning from one end of the country to the other, some of them sending choking smoke into large parts of the United States.
Rebecca Alty, Yellowknife’s mayor, told the Canadian Broadcasting Corporation that as of early Friday morning 5,118 cars and trucks had crossed a bridge on the only highway out of the city to safety. A combination of scheduled airline flights, chartered and military planes, she said, had airlifted 1,500 people out of the city and thousands more were expected to fly out on Friday.
Despite the deadline, Ms. Alty said that the highway and the airport would remain open until everyone other than essential workers and firefighters had departed, although there remained the possibility that smoke or flames could force them to be closed, cutting off the city.
“This fire has been burning for the past month so residents are aware of how the highway can open and close at a moment’s notice,” she told the broadcaster, adding that most of the city’s citizens were leaving “voluntarily and willingly.”
Addressing those residents reluctant to go, the mayor warned holdouts that all services and shops, including grocery stores, were now closed and that fire officials anticipated that the city would likely be enveloped in dense choking smoke.
While firefighters were powerless to block the smoke, the city has taken several steps it hopes will keep the fire out of Yellowknife. It is expected to reach the city limits by the weekend.
About 150 trees have been felled to create a buffer zone between the fire and city. Sprinklers are dousing the area with 1,000 gallons of water an hour as planes called waterbombers unload more water and fire retardant chemicals.
Members of the Canadian Armed Forces were assisting the local authorities to create fire breaks around the western part of Yellowknife and Dettah, a nearby hamlet, Bill Blair, minister of national defense, said at a news conference on Friday.
In British Columbia a fire that started on Aug. 15 made its way into a residential neighborhood of West Kelowna, a suburban municipality in the area, which has a metropolitan population of about 200,000 people.
Fire officials said that there was “significant structural loss” in a West Kelowna neighborhood on Thursday night although they had no count for the number of buildings destroyed. Houses remained under threat or on fire late Friday morning.
“It was a devastating night,” Chief Jason Drolund of the West Kelowna Fire Department told reporters. “We fought a hundred years of fires all in one night.”
Chief Drolund said that at some points police officers who had been ordering people to evacuate became trapped by the fire and had to be rescued. Other people went into nearby lakes to avoid the fire.
Strong wind arrived on Thursday, expanding the Kelowna area fire and impeding efforts to control it. Embers from the fire were carried over Okanogan Lake setting off spot fires within the city of Kelowna that were extinguished.
The winds from the front were expected to diminish later Friday.
Pablo Rodriguez, Canada’s minister of transport, told a news conference that the decision by Meta to block news from Facebook users’ feeds in Canada had hindered the ability of residents of Yellowknife to be informed about the evacuation. The technology company took the step after Canada passed legislation requiring Meta to compensate news organizations for the use of their material.
Some residents in community Facebook groups found workarounds by pasting news article links, with added spaces or text in the link to bypass the block, and adding instructions on how to restore them.
Mr. Rodriguez said the government will ask Meta to end its block, calling it “unacceptable.”
The air quality in Yellowknife is expected to deteriorate over the weekend, said Terri Lang, a meteorologist at Environment and Climate Change Canada. A high pressure system is slated to curb gusting winds, but it also means there will be a “very little chance of rain,” Ms. Lang said.