MONTREAL -- The greater Montreal area needs to brace for yet another heat wave, Environment Canada warned today.

This weekend’s heat is expected to last until Sunday and potentially through Monday. The hottest day is forecast to be Saturday, with humidex values that could go over 40 in parts of southern Quebec.

Daytime highs will be near 30 degrees every day, the forecasters said, and nighttime highs will stay above 20.

The City of Montreal defines a heat wave as three days in a row where the temperature stays at or above 33 degrees on average during the day and doesn’t dip below 20 degrees at night.