Flooding possible in Toronto as rain batters southern Ontario

Torontonians are being warned of potential flooding near waterways as rain batters southern Ontario.

The Toronto and Region Conservation Authority issued a flood outlook message Saturday morning, advising that all shorelines, rivers and streams in the region should be considered dangerous as rainfall may cause water levels to change rapidly.

Environment and Climate Change Canada has much of southern Ontario under yellow rainfall warnings, forecasting up to 40 millimetres of rain and possible thunderstorms.

The weather agency issued more serious orange rainfall warnings in and around Ottawa and cottage country, where up to 50 millimetres of rain could fall.

The Toronto conservation authority says the ground is already saturated from a previous April shower, which will limit its ability to absorb more rainfall.

The conservation authority is also warning that heavy localized rain from thunderstorms could cause flooding in flood plains and low-lying areas.

This report by The Canadian Press was first published April 4, 2026.

Kathryn Mannie, The Canadian Press