Canadian wildfires will send worsening smoky air across the country in coming days after rain failed to fall in areas of Quebec where the fires are most active, officials said.

Drifting smoke from the wildfires has lowered curtains of haze on broad stretches of Canada and the US, pushing into southern Illinois, Indiana, Ohio, and parts of West Virginia.

Canadian officials say it is the nation’s worst wildfire season ever and they expect air quality to remain a concern through the summer, as long as the fires continue.

It started early on drier-than-usual ground and accelerated quickly, exhausting firefighting resources across the country, fire and environmental officials said.

Environment and Climate Change Canada meteorologist Steven Flisfeder said smoke will move across Quebec and Ontario over the next few days, and air quality will deteriorate as a result.

“As long as the fires are burning and the smoke is in the atmosphere it is going to be a concern not just for Canadians but Americans as well,” he said.

Mr Flisfeder said the smoky, hazy skies will persist unless rainfall provides sufficient help to firefighters in controlling the blazes.

“It’s important to note that the highest amounts of rain were not received in those areas where most active forest fires are,” he added.

Meanwhile, Nasa said smoke from wildfires in northern Quebec has reached Europe. The American space agency said satellite imagery from Monday showed smoke extending across the North Atlantic Ocean to the Iberian Peninsula, France and other parts of western Europe.

There are 490 fires burning nationally, with 255 considered to be out of control. Quebec’s forest fire prevention agency is reporting 110 active fires.

Canada has already surpassed the record for area burned. The Canadian Interagency Forest Fire Centre reported this week that 29,393 square miles of forest and other land has burned across Canada since January 1. That exceeds the previous record set in 1989 of 29,187 square miles, according to the National Forestry Database.

Almost 1,200 vulnerable people from Cree communities are among the evacuees who have fled northern Quebec because of wildfires and smoke.

Dr François Prevost of the Cree health board said the evacuation process has gone relatively well, but he added that the situation poses particular health, logistical and cultural challenges.