Suncor Energy has shut down its 215 000 barrel-per-day Firebag oil sands site in northern Alberta and curtailed some production as a precaution due to a wildfire about 8 km away, according to the company and an Alberta government minister.

Suncor, Canada's second-largest oil producer, said the facility will be kept ready to resume full operations as soon as possible once it is safe to do so.

The company added that it was keeping only essential workers at the facility, which lies roughly 100 km northeast of the oil sands hub of Fort McMurray, and that there was no risk to its other operations or the Firebag airport.

Alberta's Minister of Forestry and Parks Todd Loewen said Firebag had been shut down on Wednesday night out of caution.

There are more than 60 fires across Alberta and officials have rated the danger in the province's north as very high to extreme, he added.

Canada is the world's fourth-largest oil producer and more than two-thirds of its five-million barrels a day of crude comes from Alberta's oil sands.

Imperial Oil, whose Kearl oil sands mine is about 20 km north of Firebag, and Cenovus Energy, whose Sunrise facility is to the south, said their operations had been not affected at present.

"We are closely monitoring the evolving wildfire activity across northern Alberta, including near our Sunrise facility," Cenovus said in a statement.

The blaze threatening Suncor's site is part of the out-of-control Firebag Complex of wildfires, which is comprised of several new lightning-caused fires, according to Alberta's provincial wildfire agency.

Weather forecasts show an extended period of hot weather will settle over Western Canada in the coming days, with temperatures expected to exceed 30 degrees Celsius by next week.

So far the wildfire season in Canada has been much quieter than last year, when more than 6 600 fires scorched a record-breaking 15-million hectares, an area roughly seven times the annual average.

But large swathes of western Canada are still abnormally dry due to ongoing drought and wildfire season tends to peak in July and August.