A special weather statement has been issued for much of northwestern Ontario.
In addition to a heat warning, Environment Canada is warning of severe thunderstorms.
As much as 40 millimeters of rain could fall overnight until Saturday morning.
Strong wind gusts in thunderstorms and even hail are included in the weather warning.
Multiple rounds of thunderstorms are expected to track over northwestern Ontario beginning overnight and continuing through Friday.
Areas affected are Kenora, Dryden, Fort Frances, and Sioux Lookout.
