A massive wildfire in Canada’s western province of British Columbia sparked additional evacuation orders early Friday, as firefighters raced to evacuate all residents of the remote northern city of Yellowknife.

Early Friday, a state of emergency was issued in Kelowna, a city roughly 300 kilometers (180 miles) east of Vancouver with a population of about 150,000 people, and residents were advised to flee. On Friday, the hills around the city glowed in the early morning light.

“Residents under Evacuation Alert are advised to be ready to leave their home at a moment’s notice,” the city said in a statement, adding that people should prepare to be away from their home for an extended period of time.

The evacuation orders were issued after wildfires that were discovered on Tuesday jumped Lake Okanagan, sparking spot wildfires in Kelowna.

Further to the east, the massive blaze threatening Yellowknife, the Northwest Territories’ capital city, made little progress on Thursday, but changing winds mean it could reach the outskirts by the weekend, said Mike Westwick, the territories’ fire information officer.

“The next two days are absolutely critical and will be some of the most challenging of the season,” he told the Canadian Broadcasting Corp early on Friday.

The fire is about 15 km (9 miles) northwest of the city, but changing winds are expected to drive it closer.

“We’re going to be putting everything we have into slowing that progression down. We’re going to be throwing aircraft at it and when it’s safe, we’re going to be throwing people at it,” Westwick said.

Teams were cutting down vegetation to create fire breaks, setting up sprinkler systems, and might even set deliberate fires in an effort to keep the blaze at bay, he said. This tactic is designed to deprive a wildfire of the fuel it needs to spread.

People were still leaving the city of around 20,000 under an evacuation order that was issued on Wednesday. Fires were burning on either side of the only highway out of town, and smoke was obscuring the view – but the road was still open, Westwick said.

Some 10 evacuation planes ferried about 1,500 people out of Yellowknife on Thursday and about 22 flights were due out on Friday, while scores of people left via road, authorities said.

“Nobody envisioned an event of this scale. It’s still really stressful. There are a lot of people still left in Yellowknife that are freaking out,” said resident Tebbia Teoncey, who was evacuated to Edmonton, Alberta.

The expanse of fire risk and disruption to life and land underscores the severity of this year’s worst-on-record Canadian wildfire season, with more than 1,000 active fires burning across the country. New data released early Friday show there were 236 active fires in the Northwest Territories.

DRY CONDITIONS

Experts say climate change has exacerbated the wildfire problem. Drought has been a contributing factor to the number and intensity of this year’s fires, officials say, with high temperatures exacerbating the situation. Much of Canada has seen abnormally dry conditions.

Around 65% of the Northwest Territories’ 46,000 population looked set to be evacuated.

As the number of evacuees in Grande Prairie and St. Albert, on the northern outskirts of Edmonton, increased, both cities announced their centers reached their full capacities and redirected all arriving evacuees to a new center in Leduc south of the capital city of Edmonton.

Among them was the Gour family from the town of Hay River.

When they received an alert on their phones while camping out, the family was left uncertain about where their son, Liam, 13, was going to land as he was returning from a cadet trip in the neighboring territory of Yukon.

As the family made their way toward Alberta, what mattered most to Paula Gour was her family.

“The only thing that I had in mind was that I had the kids, the dogs, and we had each other and just to get out of there. That’s all you can really think about at that time,” she said.

British Columbia is under the threat of dry lightning, igniting more blazes in its sun-baked forests. The province has suffered unusually intense blazes this year and officials are warning residents to prepare for extreme fire conditions.

The Pacific province has warned that the next 24 to 48 hours could be the most challenging from a fire perspective this year.