Flash flooding hits Montreal’s West Island, South Shore after torrential thunderstorms
Posted June 20, 2026 7:04 pm.
Last Updated June 20, 2026 7:30 pm.
Torrential rainfall from a series of strong thunderstorms triggered flash flooding across parts of Montreal’s West Island and the South Shore on Saturday, leaving roads underwater and some homes damaged by rising water.
Environment Canada issued an orange weather warning for the West Island, warning of flash flooding as rainfall totals surpassed 100 millimetres in some areas. Conditions were expected to improve later in the evening.
Municipal crews, Montreal police (SPVM), and Montreal firefighters (SIM) were deployed to assist residents and respond to flooded streets and properties.
SIM confirmed that many houses were affected by the flood and had damaged basements.
“Teams are on the ground, were trying to help as best as we can,” said Jim Beis, mayor of Pierrefonds-Roxboro. “This quantity of rain is almost virtually impossible to manage. We are expecting some damages to come from it.”
Flash flooding was reported in several communities, including Pierrefonds, La Prairie and Saint-Constant. Authorities said some homes in the West Island took on water, while numerous roads were inundated or experienced significant water accumulation.
Over 38mm of rain has fallen at Trudeau Airport in the last couple of hours.
The storms moved southeast across portions of Laval, Pierrefonds, Dorval and central Montreal before reaching the South Shore. Forecasters reported widespread lightning, torrential rainfall and occasional hail.
Severe thunderstorm watches and warnings remained in effect for parts of southwestern Quebec, including the Montreal region, through Saturday evening.
