A smoky summer is expected in parts of Canada as wildfire season begins. Here's how to prepare now

People in southern Ontario should start preparing now for the potential of smoke hanging over this part of the province during the upcoming wildfire season, one researcher says.

"The most important thing is to act early," Amy Li, an assistant professor in the department of civil and environmental engineering at University of Waterloo, told CBC Kitchener-Waterloo's The Morning Edition.

She suggested taking two important steps:

With wildfires will come warnings about PM 2.5, which is the particulate matter in smoke, Li said. The small particles have a diameter equal to or smaller than 2.5 micrometres. 

"As you can imagine, this is really small and exposure to elevated concentrations of PM 2.5 can cause adverse effects to the respiratory system and also the cardiovascular system and especially for vulnerable populations including children, people with respiratory disease or older people," Li said.

She noted on any given day in Waterloo region, the PM 2.5 concentration would be between five and 20 or 25 micrograms per cubic metre.

During some of the smokiest days in 2023, southern Ontario saw 250 micrograms per metre cube, "even close to 300 microgram per meter cube."

That happens even though the fires aren't necessarily in southern Ontario.

"Particles are so small, so they can remain suspended in air for a very long time. And then with the right or maybe the wrong wind condition, they can travel a very long distance. And that's why the pollutant concentration is high even if the wildfire is not in our region," Li said.

Ontario's fire season officially started Monday and runs through Oct. 31.

Following Canada's worst wildfire season on record last year, experts and community leaders across northwestern Ontario have expressed concerns about how the 2024 season will play out. 

The province reported more than 700 fires and 441,000 hectares of forests burned between April and October 2023 — almost three times as many hectares as the 10-year average.

Ontarians should expect a more active wildfire season this summer because of the milder winter, said Anabela Bonada, manager and research associate at the Intact Centre for Climate Adaptation at the University of Waterloo. 

"We didn't have much of a snow pack out here in Ontario, especially in southern Ontario, and that means our ground is not as protected and it's not getting as much moisture," she told CBC News.