"I've lived in Port Alberni since 1956 and this is one of the biggest fires we've ever seen," Russ Wetas, 69, told AFP as smoke from Mount Underwood filled the sky behind him.

The wildfire service in the west coast province of British Columbia has listed the Mount Underwood fire as "out of control," meaning it is expected to spread further.

But it remained unclear if Port Alberni, roughly 10 kilometers (6.2 miles) north, will be evacuated.

On the opposite end of the vast country, in the easternmost province of Newfoundland and Labrador, parts of the capital St. John's received evacuation orders on Tuesday, following several days of intensifying fire.

A wildfire was also burning Wednesday on the outskirts of Halifax, a major city in the eastern province of Nova Scotia, with a population of nearly half a million.

This is already Canada's second-worst wildfire season in terms of landmass burned, based on figures dating back to 1983.

So far, 7.4 million hectares (18.3 million acres) have been scorched -- an area nearly as large as Panama -- putting 2025 past the 7.1 million hectare mark from 1995.

But this year is not expected to pass 2023, when 17.3 million hectares burned, an extraordinary toll that focused global attention on the growing threat of wildfires boosted by human-induced climate change.

Smoke from this year's wildfires has put tens of millions of people under air quality alerts in both Canada and the United States. The haze has even crossed the Atlantic, affecting people in western Europe.

There were more than 700 wildfires burning across Canada on Wednesday, including 161 considered out of control, with nearly every province and territory impacted.

Mount Underwood is on Vancouver Island, making the blaze there part of a worrying trend of increased wildfire activity near the coast.

Experts have said that historically coastal areas did not burn, but more serious wildfires near the ocean are being recorded, even if they remain less intense than blazes further inland.

"This is a fire that hasn't really been seen on Vancouver Island," John Jack, a First Nations chief and regional official, told the public broadcaster CBC.

Ted Hagard, who works at Port Alberni's paper mill, told AFP he had been watching the fire's progression on social media but needed to see it for himself.

It's "insane how huge it is," the 46-year-old said, standing on the shores of a lake adjacent to Mount Underwood.

Canada is experiencing a rise in conditions that are conducive to fires, experts say, linking the trend to climate change, which has caused elevated temperatures, reduced snow, shorter and milder winters, and earlier summer weather.