Thunder Bay 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.
On Lake Superior in northwestern Ontario, the city’s flood risk is shaped by the lake’s vast size and the rivers draining into it. 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