A severe thunderstorm watch for Thunder Bay ended by late Monday morning, after a night of dangerous weather that brought heavy rain, strong winds, and the risk of large hail to the Ontario city.
Environment Canada issued the watch at 11:27 p.m. on Sunday, July 19, 2026, warning of storms capable of producing damaging wind gusts, quarter-sized hail, and utility outages. The alert was in effect through the morning of July 20, with the Monday forecast warning of wind gusts up to 100 km/h and hail up to toonie size. By 11:30 a.m. Monday, all watches had been lifted.
At 7:00 a.m., the city was already seeing a thunderstorm with light rain, 100% humidity, and visibility cut to just five kilometres. Winds from the north-northeast reached 14 km/h as the system moved through.
Residents can expect more unsettled conditions through the day. The forecast calls for a 60% chance of showers and a continuing risk of thunderstorms, with a high of 26 degrees Celsius that will feel closer to 34 with the humidity. Southwest winds are expected to gust to 40 km/h.
A yellow air quality warning also remains in place for Thunder Bay because of smoke drifting from wildfires in northwestern Ontario. Environment Canada rates the health risk as moderate and warns of poor air quality and reduced visibility. Some improvement is possible with the morning showers, but smoky skies may persist.
