Ottawa sits in the Great Lakes basin in Ontario, where a humid continental climate brings precipitation fairly evenly through the year, with the biggest flood risks coming from spring snowmelt and intense summer thunderstorms.
Canada’s capital sits at the confluence of the Ottawa, Rideau, and Gatineau rivers, all of which are closely monitored during the spring melt. Lake-effect weather patterns and the basin’s many rivers mean local flooding can develop quickly during a strong spring melt or a slow-moving summer storm, and Environment Canada’s radar network is a key tool for tracking both. Learn more: Flash Flood Warning Signs on Radar · Open the full Rain Map