Wildfires in Canada's oil city of Fort McMurray this year caused CAN $3.58 billion ($2.75 billion USD) in damages, according to estimates from insurers on Thursday, making it the country's costliest disaster ever.

The inferno swept through the Alberta city in May, dislocating about 100,000 people and laying waste to hundreds of thousands of hectares (more than a million acres), including thousands of homes and businesses.

"This wildfire, and the damage it caused, is more alarming evidence that extreme weather events have increased in both frequency and severity in Canada," said Don Forgeron, president of the Insurance Bureau of Canada (IBC), which said the cost of the damage was more than twice that of the previous record-holder, the 2013 southern Alberta flood, which totaled CAN $1.7 billion in insurance claims.