Canadian wildfire smoke is back again. How bad will it get?

USA Today

05-06-2025

In June 2023, a surreal glowing orange haze descended on New York City and across other East Coast locations as winds concentrated and redirected smoke from Canada wildfires. The smoke eventually lessened, but continued causing widespread unhealthy air quality in the United States throughout the spring and summer.
There are signs that this summer could bring a similar problem, as June 2025 brings hazy skies and air quality concerns in some areas.
The bad news: Smoke will likely be an ongoing health hazard across North America for the next few months.
"Communities across both Canada and the United States should stay informed about air quality advisories and be prepared for potential health impacts related to smoke exposure," atmospheric scientist Djordje Romanic of McGill University told USA TODAY in an e-mail June 4.
Some good news
The circumstances that led to the smoky chaos of 2023 were unique.
Canada didn't just break its wildfire records that year, it obliterated them. Nearly 58,000 square miles of the nation burned — an area about the size of Illinois — in more than 6,500 wildfires coast-to-coast from April to October, according to revised numbers from the Canadian Forest Service.
And weather patterns acted in a complex dance to redirect that smoke to the United States.
"Not at the same time, but one weather pattern would be succeeded by another weather pattern that were responsible for transporting smoke across Canada and the United States," Romanic said.
2025 looks smoky, but not that as smoky
So far this year, wildfires in Canada have burned nearly 7,685 square miles, according to the Canadian Interagency Forest Fire Centre. While that's about four times the average, it's still well below the 11,766 square miles that were scorched as of this date in 2023, which remains the nation's worst wildfire season on record.
Romanic said the summer forecast by Environment and Climate Change Canada showed continued hot and dry conditions throughout this summer, particularly in northern Ontario and the western provinces. "We expect a hotter summer than normal," he said.
"Such an environment is likely to sustain an above-average fire season, though it may not reach the scale of 2023."
What weather pushes Canadian smoke into the US?
Some of the weather patterns that transport smoke from Canada to the United States include northwesterly winds behind cold fronts that pass over Canada and move into the United States, Romanic said.
Also, high-pressure systems (ridges and anticyclones) over central and eastern North America can trap smoke close to the ground due to the large-scale subsidence (sinking) associated with them, he added.
In addition, he said that at higher altitudes, if the smoke rises there, certain jet stream alignments can transport smoke particles from Canada to the United States.
A tricky science
As for what's going to happen with smoke this summer, Christy Climenhaga, a scientist from Environment and Climate Change Canada told USA TODAY June 5 that "smoke forecasting is a tricky science." She said it depends on a number of factors, including the location of both the source fires and the end location, how big the fires are, along with the weather patterns in place at the time.
In 2023, a predominant large-scale jet-stream pattern featured a large ridge in the western United States and Canada, and a trough across the East. This allowed the fires to burn under hot, dry skies and the smoke from the fires to funnel into the eastern US.
"It can get stuck in this persistent pattern for a while," she said. With a smoky summer forecast across Canada this year, this pattern could again spread smoke downstream into the U.S. throughout the summer.
Contributing: Keith Matheny, Detroit Free Press