The village of Lytton in the interior of southern British Columbia has sizzled under an all-time high temperature for Canada, reaching 46.1C.
The reading on Sunday by Environment Canada surpassed the previous national high of 45C, which was set in Saskatchewan in 1937.
As the US Pacific Northwest sweltered to the south, a heat warning was also in effect for most of western Canada, and the weather agency said numerous daily temperature records had been broken right across the province of British Columbia.
Environment Canada expects temperatures to begin cooling on Tuesday.
In the coastal city of Vancouver, where the temperature peaked at 31C at mid-afternoon on Sunday, many people headed to the beach, though the crowds appeared smaller than usual in the sweltering heat.