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The latest heat wave to hit eastern Ontario and western Quebec is expected to be at its most punishing later Tuesday, with some locations reaching the hottest temperature of the year so far.
Tuesday’s highs are forecast to reach the mid-30s with humidity around the low 40s. At 2 p.m. it was 32 C with humidity making it feel like 42 at the Ottawa International Airport.
The temperature is expected to stay above 20 C overnight with lingering humidity.
If Ottawa reaches the forecasted high of 35 C it will be the hottest day of 2026. Other communities such as Brockville and Kingston could also set daily heat records.
The heat has prompted some businesses to take a break.
“We decided to shut down, essentially, for the next two days,” said Sarah Bowen, social media manager for the Heart and Soul Café in Dunrobin on Tuesday morning.
“We just want to keep our staff safe. The kitchen temperature is going to get out of hand, even with air conditioning and all the fans running.”
WATCH | Some of Tuesday’s scenes:
How Ottawans are beating the heat
The latest heat wave to hit eastern Ontario and western Quebec could see the hottest temperature of the year in some locations. The CBC’s David Fraser spoke to Ottawans about how they’re handling it.
Environment Canada first issued heat warnings for the region on Sunday afternoon. Monday peaked around 30 C in Ottawa late in the afternoon with humidity making it feel like 35.
The warnings are expected to end Wednesday as both temperatures and humidity slowly ease.
Many municipalities including Ottawa offer lists and/or maps of public places to cool off, which may included dedicated cooling centres.
People should be on the lookout for signs of heat exhaustion which include headaches, dizziness, thirst and fatigue, the weather agency said.
Anyone experiencing signs of heat stroke should call 911, they added.
The heat is contributing to an extreme fire risk in the Pontiac and some local parts of Algonquin Park. Risks are considered very high or high elsewhere, with restrictions in place including a western Quebec burn ban.
Severe thunderstorm watches
Ottawa, Cornwall and western Quebec are now under severe thunderstorm watches Tuesday afternoon and evening.
Risks include wind and hail along with lightning. Western Quebec could see hail or a tornado.
“It’s a complicated day today,” said Peter Kimbell, a warning preparedness meteorologist at Environment Canada.
Kimbell said wildfire smoke drifting in from the north is also in the mix, reducing the sun’s intensity and tempering the heat to some extent.
All local alerts are yellow, the lowest and most common level of Environment Canada’s three-colour scale it introduced in 2025.
