The tornado warning for parts of Ontario has been lifted, ending the last of several alerts that sprang up on Sunday evening as a series of violent storms moved across the province.
Environment Canada said an unstable air mass, stretching from north of Lake Erie to Greater Sudbury was the cause for concern.
Warnings about twisters, together with hail and thunderstorms, were in effect for Sarnia, Sudbury, Manitoulin Island and other areas north of Georgian Bay.
There have are no reports of damage or injuries.
Heavy rain and thunder is still expected in the London area.