Residents in Sarnia, Ontario, are being warned to prepare for significant rainfall starting Tuesday, March 10, 2026, which could lead to localized flooding across the region. A series of weather systems is expected to bring between 20 and 40 mm of rain through Wednesday, March 11, 2026, according to Environment Canada.
Weather experts say that even more rain could fall in specific areas if thunderstorms develop over the next two days. Because the ground is currently frozen or already soaked from earlier winter weather, it has very little ability to soak up the incoming rain.
This lack of absorption creates a high risk for flash floods and water pooling on local streets. Residents should be careful near low-lying areas and are advised to never drive through flooded sections of the road.
The St. Clair Region Conservation Authority is monitoring the local waterways and will provide updates if conditions change. Community members are encouraged to watch for local alerts and report any severe weather they see to federal authorities.
