Some 486 fatalities were recorded over the past five days in British Columbia alone, a 195% increase on the usual amount over that period.

Canadian Prime Minister Justin Trudeau offered condolences to families of the victims, many of whom were elderly.

Abnormally high temperatures have been recorded across North America.

British Columbia Chief Coroner Lisa Lapointe said on Wednesday: "It is believed likely that the significant increase in deaths reported is attributable to the extreme weather British Columbia has experienced and continues to impact many parts of our province."

She said many of those who died in the heatwave had lived alone in homes that were not ventilated.

Ms Lapointe added that the western province had only seen three heat-related deaths over the past three to five years.

On Wednesday evening, the town of Lytton, British Columbia, was evacuated because of a wildfire - a day after it recorded Canada's highest ever temperature of 49.6C (121.3F).

Mayor Jan Polderman told CBC News: "The whole town is on fire. It tooks like a whole 15 minutes from the first sign of smoke to all of a sudden there being fire everywhere."

The heat over western parts of Canada and the US has been caused by a dome of static high-pressure hot air stretching from California to the Arctic territories. Temperatures have been easing in coastal areas but there is not much respite for inland regions.

The weather system is now moving eastwards over the Prairie provinces - Alberta and Saskatchewan and parts of Manitoba have been placed under Environment Canada heat warnings.

Janice Houldsworth, who lives in the British Columbia community of Castlegar, told the BBC she had not ventured outdoors for four days. "I've never experienced anything like this in all my 70 years," she said.

"We have blackened out all the windows, have fans running 24/7 constantly spraying with mist, cold foot baths, and showers and [are] drinking tons of liquid."

In Vancouver alone, heat is believed to have been a contributing factor in the deaths of 65 people since Friday.

At an affordable housing event in Kanata, Ontario, Mr Trudeau described heatwaves as a growing problem, and went on to talk about climate change.

Canada's southern neighbour, the United States, has also seen extreme heat.

In the US Pacific Northwest on Monday, temperatures hit 46.6C (116F) in Portland, Oregon, and 42.2C (108F) in Seattle, Washington, the highest levels since record-keeping began in the 1940s, the National Weather Service said.

In Oregon, authorities say at least 63 people have died from health issues related to the hot weather over the past few days. Forty-five of those deaths were recorded in Multnomah County.

At least 16 people have died in Washington state's King and Snohomish counties.

US President Joe Biden has also linked the heatwave to climate change in a speech.

BBC News