Heat warning this week after storm dumps up to 100mm of rain on Montreal
Posted July 14, 2025 7:06 am.
Last Updated July 14, 2025 5:58 pm.
The city is gearing up for a heat warning on Tuesday and Wednesday after up to 100 millimeters of rain fell in the Montreal area on Sunday as violent thunderstorms swept across Quebec, causing flooding and numerous power outages.
According to preliminary data from Environment and Climate Change Canada (ECCC), released Sunday evening, the Island of Montreal received 70 to 100 millimeters of rain.
“We had some severe thunderstorms roll through in the afternoon,” said Ian Hubbard, a meteorologist for ECCC. “Large area of the city saw significant rain, a lot of flooding.”
“We saw some really high rainfall rates, 58 millimeters in an hour at the airport,” he added. “We saw some other reports of more than 50 millimeters in less than an hour, and we even saw a report of 100 millimeters in about an hour and a half. So that’s an awful lot of rain to come down in a very short timeframe.”
On the North Shore, still in the metropolitan area, 80 to 110 millimeters of rain fell. The South Shore, meanwhile, received 40 to 70 millimeters of rain.
These significant amounts of rain, often falling quickly during thunderstorms, flooded streets and homes. Several highways were also submerged, while flights were delayed at Montreal-Trudeau Airport.
As the storms raged, nearly 100,000 Hydro-Québec customers were without power by late afternoon. As of Monday morning, fewer than 5,000 addresses were still affected by outages.
On social media, Public Security Minister François Bonnardel assured that his ministry’s teams were in contact with the municipalities affected by the rain and storms.
“We are also in contact with partners such as (Transports Québec), (Hydro-Québec), and the municipalities,” Bonnardel emphasized.
Les équipes du @secpubliqueqc sont en contact avec les municipalités touchées par la pluie et les orages dans les régions des Laurentides, de Lanaudière, de la Montérégie, de Laval et de Montréal. Le centre des opérations gouvernementales va rester vigilant alors que les orages…
— François Bonnardel (@fbonnardelCAQ) July 13, 2025
After passing through the Laurentians, Lanaudière, Montérégie, Laval, and Montreal, the storms moved toward the Quebec City region, where the programming for the final evening of the Summer Festival was disrupted.
Most of the scheduled concerts were canceled, but the headliners were still able to perform at the end of the evening. On the Plains of Abraham, Puerto Rican singer-songwriter Farruko was able to perform.
The heat persists
According to ECCC’s forecast, the sun will shine early in the week, but the heat will return on Tuesday and Wednesday.
To start off the work week, Monday is seeing a mix of sun and cloud with a daytime high of 29°C.
The federal agency has already issued a heat warning, warning that maximum temperatures will range between 31°C and 33°C. With the humidity, temperatures will feel close to 40°C.
Nights will be just as hot, with minimum temperatures ranging between 20°C and 23°C.
“Both of those days, we’re going to see the humidex values reach 40,” said Hubbard. “Once we see these temperatures exceed 30 Celsius and the humidex reach 40, that’s when we’re going to issue heat warnings and that’s what we have in effect for two days.”
#WATCH: "Heat warnings in effect now," says Ian Hubbard, a meteorologist for Environment and Climate Change Canada as Montreal gears up for a hot, hot, hot week.
— CityNews Montreal (@CityNewsMTL) July 14, 2025
This after Sunday’s thunderstorms dumped up to 100 millimeters of rain on the city.
READ: https://t.co/j9GPc3nH20 pic.twitter.com/URy4eZcMRz
The warning specifically affects Greater Montreal, Lachute, Lanaudière, Montérégie, and Drummondville. Similar warnings are also in effect in Ontario.
–This report by La Presse Canadienne was translated by CityNews
