Heavy rain causes flooding and power outages across Montreal area

MONTRÉAL — Environment Canada warned Sunday that conditions remain favourable for more flooding in parts of southern Quebec, after torrential rain soaked Montreal’s West Island and communities south of the city a day earlier.

Environment Canada said up to 150 millimetres of rain fell in parts of western Montreal and the South Shore in just a few hours Saturday. The agency warned that more showers and thunderstorms were possible Sunday and noted that the ground in areas hit by the heaviest rain may not be able to absorb much more water.

In Montreal’s West Island, Montreal firefighters spent Saturday evening assisting residents in the borough of Pierrefonds-Roxboro and the city of Dollard-des-Ormeaux, where heavy rainfall flooded streets and homes. The Montreal fire department said late Saturday that the situation had stabilized.

At a news conference Sunday in Dollard-des-Ormeaux, Montreal fire department spokesperson Martin Guilbault said crews were still going door to door in some flooded neighbourhoods. “Our objective right now is to make sure all residences are safe,” he said.

Dimitrios Beis, mayor of Montreal’s Pierrefonds-Roxboro borough, said “hundreds of homes” had been flooded since Saturday afternoon.

Beis said the borough opened a temporary shelter at the Pierrefonds arena on Saturday and mobilized volunteers to help vulnerable residents remove belongings from their homes.

Errol Johnson, deputy mayor of Dollard-des-Ormeaux, said the city was facing “a very difficult situation” following the storm.

Montreal police were also called in to assist with the flooding response. Montreal police spokesperson Anthony Dorelas said officers closed several roads Saturday in Montreal’s West Island, including sections of Boulevard Pierrefonds and Boulevard Jacques-Bizard.

The force said its assistance to emergency responders ended around 2 a.m. Sunday.

Power outages continued to decline Sunday after storms left about 20,000 Hydro-Québec customers without electricity Saturday night. On Sunday afternoon, the utility reported 51 outages affecting 1,312 customers across Quebec.

Most of the remaining power outages were in the Montreal region, particularly in the West Island communities of Pierrefonds and Dollard-des-Ormeaux.

Hydro-Québec said Sunday morning that some outages were preventive and that crews were continuing to restore electricity to affected customers.

The storms also disrupted flights and ground operations at Montreal-Trudeau International Airport on Saturday evening. The airport urged travellers on social media to check their flight status before heading to the terminal.

Anne-Sophie Hamel, an airport spokesperson, said a lightning alert in effect from 3 p.m. to 7:30 p.m. brought operations at the airport to a standstill on Saturday. During that period, no aircraft were able to land or take off, and 25 flights were diverted.

Air Canada said flight disruptions were expected throughout Sunday. Hamel said the airport was operating normally Sunday, but the effects of the lightning alert were still being felt through flight delays and cancellations, as well as baggage delivery disruptions.

According to the airport’s website, a few flights scheduled for Sunday morning were cancelled or rescheduled.

On Montreal’s South Shore, the city of Saint-Constant, about 25 kilometres southwest of downtown Montreal, declared a local state of emergency Saturday night after heavy rainfall caused flooding and damage to residential properties and road infrastructure.

By Sunday morning, city officials said conditions had stabilized and the local state of emergency had been lifted. Most roads had reopened and residents could proceed with water removal efforts without fear of sewer backflow.

Quebec Domestic Security Minister Ian Lafrenière said Sunday afternoon on X that he was monitoring the situation closely and that provincial officials were in contact with affected municipalities.

This report by The Canadian Press was first published June 21, 2026.

The Canadian Press