Wildfires have burned more than 2.7 million hectares in Canada so far this year, eight times more than the last three decades' average, officials said Thursday, as more than 200 blazes remained active.

After major flareups in the west of the country in May, notably in the Prairies provinces of Alberta and Saskatchewan, massive firefighting efforts shifted in the past week to Nova Scotia on the Atlantic coast.

"These conditions this early in the season are unprecedented and of course they are deeply concerning to all Canadians," Emergency Preparedness Minister Bill Blair told a news conference.

There are currently 211 wildfires raging across the country, including 82 that are burning out of control, he said.

And the arrival of an extreme heat wave and strong gusts of winds in the east risks leading to "extreme fire behavior," according to firefighters.

In Nova Scotia, 16 fires were active on Thursday. One is threatening the northwest suburbs of the province's main city of Halifax and forced the evacuation of more than 16,000 local residents. It now appears to be partially under control.

But another fire near Lake Barrington continues to pose a challenge for fire crews after burning more than 20,000 hectares. It is the largest fire ever recorded in the province.

More than 2,000 area residents in the path of the fast-moving blaze were forced to flee at a moments notice earlier this week.

"We are far from being out of the woods. We are still dealing with a very dangerous and volatile situation," local natural resources official David Steeves said.

"We need Mother Nature to get on side with us on this," he added. (AFP)