Thousands of people have been forced to flee wildfires in western Canada that were triggered by abnormally high temperatures, sometimes exceeding seasonal averages by 10°C (50°F) in early May, according to government reports.

Western and central Canada, where a large part of the country's agricultural land is concentrated, are currently experiencing "abnormally dry" conditions and even "severe drought" in places, the latest survey from the Canadian government said.

In the province of Alberta, the region worst affected by forest fires, there were reports of more than 70 active fires on Friday, several of them out of control.

Some 13,000 residents were under evacuation orders, officials said.

The main focus was Fox Lake, in the north of the province, where fires extended over nearly 1,500 hectares (3,700 acres) and have already consumed a small community comprising some 20 houses.

British Columbia, on the Pacific coast, is doubly affected: several fires are active inland while the south of the province is threatened by rapid snowmelt that has raised the level of rivers, some of which burst their banks.

According to the authorities, heavy rains expected at the weekend could worsen the situation.

"Multiple days of unusually warm temperatures have generated rapid snowmelt and high streamflows across much of the BC Interior, with severe flooding underway in some areas," provincial authorities said in a statement.

"Severe flooding is possible, and extreme flooding... is plausible, in areas that receive high rainfall," the statement added.

"Peak river levels are generally expected between Saturday and Monday," it said.

In recent years, western Canada has been hit repeatedly by extreme weather, the intensity and frequency of which have increased due to global warming.

In addition to catastrophic flooding, British Columbia was also hit two years ago by the effects of a "historic" heat dome, which claimed hundreds of lives and was followed by major fires.