Ontario has had a brief break from the heat, but that is going to come to an end beginning on Friday.
On Friday, the heat will make a return, in a rather concentrated area. Areas west of Thunder Bay along the international border will see temperatures in the low thirties and overnight lows only around twenty.
The heat will continue in the same area on Saturday with similar conditions expected. Southwestern Ontario and Eastern Ontario will also see hot temperatures on Saturday. Daytime high temperatures between 31 and 34 are expected with overnight lows Saturday night of 20 to 23 degrees. Humidex values may reach 40.
By Sunday, the temperatures will fall in Northwestern Ontario. Southern and Eastern Ontario will continue to experience high temperatures in the thirties. The heat is expected to linger into next week also.
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There is also a risk of thunderstorms across the province.
Ontario has been under heat warnings for most of the summer so far. The average high for Toronto today is 27.0°C, Ottawa should be at 26.7°C, and Thunder Bay should be at 24.5°C.
It is important to stay safe during such extreme temperatures. Avoid working or exercising intensely if it is very hot or humid outside, and head for cooler conditions if your body becomes overheated.
Drink plenty of liquids and take frequent rest breaks. Be sure to maintain salt levels in your body and avoid high-protein foods.
Also, ensure to protect pets from the heat and give them plenty of water to drink.
Watch for signs of serious medical conditions, such as heat exhaustion and heatstroke.