Waterloo Region under heat warning, humidex values to hit low 40s
Posted Jul 13, 2026 07:24:42 AM.
Last Updated Jul 13, 2026 04:03:38 PM.
The heat that scorched Waterloo Region over Canada Day is back.
A yellow-level heat warning is in effect not only Waterloo Region but also across all of Ontario.
Environment Canada has much of northern Ontario under a severe orange warning, including Kenora, Thunder Bay, Fort Hope and Timmins.
Forecasters say those areas could see highs of 36 C, with the humidex making it feel as hot as 42, before letting up later Tuesday.
Environment Canada has issued less severe yellow warnings for southern Ontario, including Waterloo Region, Guelph, Woodstock, Windsor, Toronto, North Bay and Ottawa.
Temperatures are expected to reach nearly 36 C in some areas during the heat event that’s set to hit its peak Tuesday and last until Wednesday or Thursday.
“Take action to protect yourself and others – extreme heat can affect everyone’s health,” reads the alert from Environment Canada.
“Watch for the early signs of heat exhaustion in yourself and others. Signs may include headache, nausea, dizziness, thirst, dark urine and intense fatigue. Stop your activity and drink water.”
The extreme heat has led to an increase in emergency calls in the region already this summer.
During the last heat wave at the end of June, Chief of the Region’s Paramedic Services, John Riches, told CityNews local paramedics had seen a 14 to 14.5 per cent increase in calls as compared to the same period last year.
Riches pointed out that the best way to avoid having to call 911 is to simply take care of yourself.
“Make sure you stay hydrated. Make sure you stay in the shade if you can. Make sure you’re using a lot of sunscreen and wearing appropriate layers to protect your skin and yourself from this heat. And just taking care of yourself, making sure you’re eating well. All those things are very important.”
The latest weather information can be found here.
The City of Kitchener says its added staff, increased capacity, and extended hours at outdoor pools to help residents’ beat the heat this week.
The Harry Class, Wilson and Idlewood pools will be open daily until 8:45 p.m., while the Kiwanis Park pool will close at 8:30 p.m.
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