Canada’s fire season erupts, sending harmful smoke into United States

Wildfires in Canada have roared back to life, sending harmful smoke into the northern United States – an unwelcome reminder of last summer’s historic fire season that also repeatedly sent plumes of noxious haze southward.

Almost a year to the date from the explosive start to the 2023 fire season, hundreds of fires have erupted in Canada, including a dozen major and out-of-control blazes. At least 500,000 acres of land have burned so far, much of it in recent days.

Smoke from the blazes has led to air quality alerts for much of Alberta and its surrounding provinces, as well as Minnesota and Wisconsin. Edmonton was subjected to red-tinged skies and hazardous air quality over the weekend because of wildfires to its north.

International Falls, Minnesota, awoke Monday to air quality alerts, which expanded to cover a large portion of Minnesota and Wisconsin, including Minneapolis and Green Bay.

Wildfires roar to life

Even during winter, numerous blazes in Canada – known as “zombie fires” – smoldered beneath the snow. The combination of a warm and very dry winter set the stage for flames to quickly expand this spring.

Belts of extreme to exceptional drought are draped across the zone from central British Columbia to northern Alberta, where many of the worst fires rage. The majority of provincial land from Canada’s west coast to Ontario is experiencing at least moderate drought.

More than 100 fires were burning in British Columbia on Monday morning, and just shy of four dozen in Alberta. Other large blazes were scorching provinces to the east.

The largest uncontrolled fire was burning in the mining region of Manitoba near the border with Saskatchewan, about 400 miles north of the North Dakota border. It had grown to at least 86,000 acres by early Sunday since igniting three days earlier. The fire led to evacuations in the town of Flin Flon and power cuts across the region.

Farther west, a blaze near Fort McMurray in Alberta’s wooded north was also out of control. The fire, about 225 miles from Edmonton, more than tripled in size from over the weekend, according to the Canadian Broadcasting Corp. An evacuation alert was in effect there for residents to be prepared to leave if necessary.

In adjacent eastern British Columbia, another out-of-control fire was threatening Fort Nelson in the Canadian Rockies about 650 miles north of Vancouver. Some residents of that area have also been urged to evacuate.

Smoky skies return downwind into United States

The worst of the smoke from these fires has been near the source in southwestern Canada. The air quality reached Code Purple – the most hazardous level – over the weekend in an area along the British Columbia-Alberta border region, according to the U.S. government’s AirNow pollution monitoring website.

Parts of northwest Minnesota saw air quality decline to Code Red on Sunday, signifying unhealthy levels of smoke pollution; this area even briefly experienced Code Purple conditions. Much of the northern Plains and the Upper Midwest, as well as adjacent Canadian prairies, have experienced at least Code Red levels.

Smaller quantities of smoke riding along the high-altitude winds of the jet stream even reached the East Coast of the United States over the weekend.

Over the next two to three days, hazy skies and the acrid smell of smoke should continue to spread across portions of Canada, the Upper Midwest and Great Lakes. The smoke may sink southward into the eastern Plains and Midwest at times on Tuesday.

Fires in Mexico also send smoke into the United States

It’s not just Canada that is sending smoke into the United States. Mexico is also contributing to hazy conditions because of rapidly spreading fires fueled by excessive heat and drought.

A large plume of smoke from Mexico is poised to spread over far-southern Texas, the southern Gulf states and Florida in the days to come.

Like Canada, large parts of Mexico are covered by the two most extreme levels of drought. Its drought has intensified extraordinary and persistent heat, as high as 123 degrees in recent days – the hottest ever observed in May in the Northern Hemisphere, according to weather historian Maximiliano Herrera.

Human-caused climate change intensifies heat, droughts and fire intensity.

What’s next?

Unusually warm and dry conditions are predicted in British Columbia and Alberta into June, leading officials to warn of an elevated fire risk. A developing La Niña climate pattern may eventually offer more consistent rains late summer or fall reducing the threat somewhat.

More broadly, human-caused climate change will continue to elevate the fire risk in Canada because temperatures are climbing so fast in the region. The warming dries out the land surface and makes it more combustible.