Hot temperatures forced heat warnings across parts of Saskatchewan, Manitoba, Ontario, Quebec and surrounding areas.
The jump came quickly after a prolonged warm spell in Ontario, its longest since 1934, with humidex readings making it feel hotter still.
Manitoba in addition broke a daily high mark temperature record during the same stretch.
Metro Vancouver hit nearly 31 C early in the week in the early week before rain arrives Tuesday.
Authorities told residents to avoid the sun when risk peaks.