The start of the week will see the mercury pick up in southern Quebec, with Humidex values that could reach 40 in Greater Montreal.
The warning issued by Environment Canada concerns the sectors of Laval, Montreal and Montérégie where the wet weather alternating between sun and clouds will persist in part until Tuesday.
For these sectors, the federal agency predicts up to 31, even 32 degrees on the thermometer, but it will be just as hot in Lanaudière and the Laurentians with a Humidex of 36.
The same scenario is expected in the center of the province, particularly in Estrie, Quebec and Beauce, where the federal agency predicts maximums of 28 degrees and a feeling of 36.
The weather will be more cloudy and windy, but slightly warm in places, in the east of the province, particularly in Bas-Saint-Laurent and Côte-Nord.
In addition, showers are expected on Tuesday in several areas in the south and center of the province, while a cold front will cause a return to seasonal temperatures starting Wednesday.