Environment Canada has issued a weather warning for Montreal and other areas in southern Quebec.
The city is being contained by a warm air mass that started earlier this week, causing above seasonal temperatures and humidex levels that could reach between 35 and 38 degrees on Wednesday.
The normal season highs are usually 22.1 degrees at this time of the year.
Soon after, a low-pressure system could produce 30 to 50 millimetres of rain starting from Thursday to Friday.
The weather agency is reminding people to drink plenty of water and to schedule outdoor activities during the coolest parts of the day.
“If you are in an overheated location, look for a cool place, such as the shade of trees, a water fountain with splash pad, a cooling station, or an air-conditioned facility like a public building. Never leave people, especially children, or pets in a parked vehicle,” reads Environment Canada’s weather statement.
Thursday will be a high of 28, a low of 17 with showers starting in the afternoon. The humidex levels will reach 34 degrees.
On Friday, more rain.
The high will be 21 degrees, with a low of 15 and 70 per cent chance of showers.
Saturday should see a high of 22, a low of 13 and a 60 per cent chance of showers.
On Sunday, similar weather will persist for race day at the Canadian Grand Prix – a 70 per cent chance of showers, a high of 22 and a low of 14 degrees.