'It's not over': How the weather forecast will affect wildfires, firefighting efforts in Canada

Rain and cooler temperatures in the forecast for parts of Canada could offer some relief for residents and firefighters working tirelessly to extinguish the flames from raging forest fires, an expert says, while warning that the country’s fire season is not over yet.

“The cooler temperatures, the rain that we do see will help to lessen the threat, but not eliminate it,” Dave Phillips, senior climatologist at Environment Canada, told CTVNews.ca in a phone interview.

“And it will also help to scrub and cleanse the air so that people aren't breathing the kind of nasty chemicals that they were when the height of the smoke was in eastern Canada last week and a couple of weeks ago in Alberta. So I think there's a reprieve here, but hey, it's not over.”

• Climate Barometer newsletter: Sign up to keep your finger on the climate pulse

Phillips said the rainfall expected in eastern and Atlantic Canada this week will not douse all the flames, as Canada is a massive country with more than 400 active forest fires, but the precipitation observed in parts of Ontario and Quebec has quenched some of the flames, improved air quality in certain areas and led to fewer fires burning out of control.

“So they are making progress and some areas clearly have had some good, helpful precipitation, but there are still fires across the country and in particular, there's smoke,” he explained.

The cooler temperatures will also help, Phillips said, because firefighters working to extinguish the flames aren’t faced with the same “suffocating” hot temperatures and smoke.

However, he warned that matters could get worse, noting that there are typically more forest fires in July than any other month in Canada, with more thunderstorms tending to happen then and igniting fires — what he called a firefighter’s “worst nightmare.”

“Sometimes, these fires, when you get a weather system that moves in, you could have thousands of lightning strikes and this breaking up like popcorn just across the landscape — you get a fire here, a fire there,” Phillips said.

“So we've really had good practice — almost a full year’s worth of fires — and yet, the peak of the season hasn't even come close.”

Speaking about the situation in Ontario and Quebec at a media briefing Monday, Gerald Cheng, warning preparedness meteorologist at Environment and Climate Change Canada, shared a similar remark. He said the current weather forecast presents a “very precarious situation” that provincial authorities will need to keep a close eye on as they continue to battle the fires.

“Ideally, we would want a lot of rain, but that may not be the case for places where the most active fires are,” Cheng said.

“On top of that, often the rain or the showers come with a risk of thunderstorms. And if there's a risk of thunderstorms, there's going to be lightning, which can trigger new fires.”

To date, roughly 4.9 million hectares have burned in Canada this year, far surpassing the yearly average of 2.1 million hectares burned in an entire fire season. More than 1,000 firefighters have arrived from overseas to help extinguish the relentless flames.

Phillips said the fact that Canada was “bone dry” from coast to coast from the beginning of the year until the start of June is what created the kind of forest fires to start and to spread. And with weather conditions forecast to be warmer and drier than normal this summer, he predicted that Canada is in for what will likely be a long battle and stressed that Canadians will need to be “vigilant” and respect fire bans and do their best to prevent fires from breaking out.

For now, though, he said the rain and cooler temperatures are providing “a glimmer of hope” in the unprecedented fire season.

“It's better. I mean, I still think there are fires in every province, I mean even in the Maritimes, I'm sure there are some fires somewhere, but the hotspots have been reduced down in size and more and more significantly in a way. Not only are there fewer flames, but there's less smoke.”