Canadians should keep sunscreen and a fan handy as many parts of Canada are being impacted by a heat wave that is expected to last throughout the week, experts say.
Jean-Philippe Chenier, a warning preparedness meteorologist for Environment and Climate Change Canada (ECCC), said this stretch of heat has the potential to be deadly.
“We’ve seen worse, when we have a duration longer than three days, but it’s very important to take this heat wave seriously,” he said.
The scorching temperatures stem from a heat dome, which occurs when a large area of high pressure in the upper atmosphere acts as a reservoir that traps heat and humidity, according to the U.S. National Weather Service.
“We have very hot air coming from Texas and central U.S., along with humidity coming from the Gulf of Mexico,” Chenier said. “So, this is the reason, but this is a classical setup for a heat wave in southern Ontario, as well as in southern Quebec.”
Chenier added that the heightened heat is also expected to bring on severe thunderstorms Tuesday in northern and eastern Ontario, as well as southern Quebec.
Where is the heat the most intense?
According to Environment Canada, there are currently yellow alerts for heat classified under every Canadian province and territory except Quebec and B.C.
Labelled as the most common weather alert, the yellow alert is meant to symbolize “hazardous weather” that indicates that impacts are “moderate, localized and/or short-term,” but “may cause damage disruption, or health impacts.”
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Quebec is currently under an orange warning for air quality, while parts of B.C. are under a fog advisory.
“In southern Quebec, we could see humidex is as high as 40 to 44 from Wednesday right through to Saturday and only seeing a little bit of relief later in the weekend,” Global News meteorologist Peter Quinlan said.
A “high impact” yellow alert is in place for much of southwestern Ontario, as maximum temperatures of 30 to 36 C are expected until Friday and potentially the weekend, with lowest temperatures anticipated to be just 21 to 25 C.
The humidex values sit between 37 and 45.
Wider yellow alerts are also in place in Alberta, which is classified as “moderate impact.” Environment Canada states that daytime high temperatures will vary between 29 and 31 C, combined with overnight lows near 14 C. However, cooler conditions are expected by Thursday.
“The main front of the heat will be a focus on southern Ontario, where across the GTA we’re going to see temperatures into the mid-30s, especially mid-week Wednesday, Thursday in particular, with humidexes into those 40s,” Quinlan said.
“In many areas, this is the first prolonged heat wave. Most areas have seen some 30-degree highs so far this summer but this is one that’s going to last for multiple days and that usually the first one of the season is a little more startling because people aren’t quite prepared for it and it is going to potentially kick off a pretty hot summer in many areas.”
The heat will also remain intense at night, too.
“Temperatures ranging from 22, 23, up to 25 degrees, that’s for minimum temperatures that are only obtained around 4 or 5 a.m.,” Chenier said.
“So, during the evening or late in the evening when people go to bed, temperatures could still stay in the 30s or low 30s, but with the humidex 35-40 in buildings that don’t have air conditioning.”
Hotter than normal summer has been anticipated
ECCC estimated in January that 2026 “will likely be among the hottest years on record,” comparable to 2023 and 2025, and approaching 2024, the hottest year ever recorded.
Ryan Ness, director of adaptation with the Canadian Climate Institute, said climate change has served as an “amplifier” for accelerated heat.
“Canada is actually warming twice as fast in the global average, so we’re on the pointy end of the entire world heating up,” he said, adding that this is purely a result of Canada’s location in the world.
“We do have to get used to this new type of heat because it is the new reality and it will unfortunately only get worse. Even if greenhouse gas emissions were ended today, we’re still committed to 100 years or more of warming and warmer temperatures than we’ve ever seen.”
The main takeaways from the ECCC three-month summer forecast were for Canadians to expect heat and humidity this summer.
There were high likelihoods for temperatures exceeding averages across the country, with projections also showing an increased likelihood for higher-than-normal specific humidity, which can make it feel much warmer than it actually is and can hinder the body’s ability to cool itself down.
In addition, the super El Niño that is beginning to rear its head in Canada is only adding to the already-escalated temperatures.
To declare an El Niño, ocean temperatures in a particular region of the tropical Pacific must generally clear 0.5 degrees above the long-term average. A super El Niño, in contrast, happens when temperatures are more than two degrees above the average.
“It does look like this could be a very strong El Niño and we might start to see the effects of it later in summer into early fall, which might bring about a prolonged warm stretch into fall and maybe a little bit more of an extended summer period before we move into winter when those implications are a little more significant,” Quinlan said.
Many parts of western Europe are feeling the effects of a deadly, record-breaking heat wave, which saw 1,000 deaths in France last week at the height of the heat wave, the country’s public health agency said Sunday.
In Germany, a new nighttime temperature record was reported Sunday from Kubschütz, in eastern Saxony, where the temperature did not drop below 29.4 C.
#ThanksTrudeau for the OBVIOUS decade of #ChemTrails climatizing Canada to be more like India. 🤮
I’m glad to see Toronto is still the centre of the universe, and Quebec City the home of stupid language laws is Canada’s real capital. This is “Much of Canada”.
I like open air coal mines so I rigged it so their referendum can’t take place.
I like referendums on whether we should have a referendum.
That’s how I get the stupid redneck vote.
@Mel:
phuck off stupid. Heat records are being shattered.
duh…it’s summer…duh….wipe the drool off your shirt
Here go the media. It’s summertime Global. It gets hot in summer. Imagine that. Give me a break. Find something important to write about Global.
It’s summer so all the global warming oops sorry climate change alarmism is dragged out of storage and dusted off for yet one more round of “The sky is falling, The sky is falling.” Never acknowledging that most of the scientists that use to rely on the UN IPCC computer modelling have now said the modelling was wrong and the predicted ongoing increase in global temperatures have not come to pass.
not a problem in Canada. trudi banned plastic straws and put a huge carbon tax on us. all is well we are saved
Southern Ontario and Quebec isnt “much” of Canada…
Oh no hot weather in summer who would have thunk it
lol. Enjoy summer. It doesn’t last long enough.
Let’shave more Alberta open air coal mines. I won’t let them have a referendum!
Saw “experts” in the article title, and knew it was all lies.
Pass laws like UK where they can’t install AC’s in new London apartments all at the altar of climate change.
Ya and our stupid, criminal government won’t make airconditioning in highrises, mandatory. It makes you wonder how an idiot gets to be a politician when they don’t even have the mental capacity to solve a simple problem like heat exhaustion?
you mean the “machine” is going to f__ck with the weather, again
Apparently the folks at ECCC don’t know that this weather system is now called an OMEGA BLOCK. Heat Wave is so yesterday when it comes to the weather.
we out here on the bald prairie watched the national weather guy talk about a heatwave and how we should stay out of the sun. Hmmm maybe it Vancouver or Toronto, but if he had paid attention, we haven’t seen the sun in a week and they Local weather) say maybe next week the rain will stop. PS the Saskatoon weather girl with that great Ukrainian accent is a joy to hear.
By much of Canada, you mean <5%.
@Allan. The phrase used was many parts of Canada, which is true.
Much of Canada? You mean eastern Canada. Your ignorance of geography and what makes up Canada, is reason people in the west are considering separation. The west is considered part of Canada when it comes to collecting tax revenue, but the west isn’t really part of Canada when it comes to broadcasting to the Canadian’s that really matter … Ontario and southern Quebec. Shame on you!
I don’t see anything different in the forecast or feel anything worse from past summers, to be completely honest. This maybe seems like the El Nino prediction earlier this year that turned out the complete opposite. We’ve seen more rain and humidity, not less.
mid 30’s. Whoop de doo. It’s 14 right now. Believe it when I see it. More global warming B.S.
How much of this is from the Tonga volcanic eruption, which emitted unfathomable amounts of moisture into the atmosphere that scientists said could temporarily increase global temperatures for a few years? Or other volcanic eruptions.
In my small town in BC it is forecast to be cloudy with possible rain and only getting into the upper 20’s C for Canada Day. That will be the first time in over 20 years that I have lived there that it will not reach upper 30’s or low 40’s C on Canada Day. So we in BC are experiencing a cooler than normal summer this year.
You mean summer is here? Lol
The joy of living 2 blocks from the waterfront
Even when AC is failing to keep up.the beach is always close by