Sarnia's temperature is forecast to hit 20 C (68 F) Friday.
Environment Canada meteorologist Geoff Coulson says we could set a new record high.
"We have a forecast high of 20 C and the current record is 20.0 C from back in 1975, so all it would take to break the record would be getting up to 20.1 C, 20.2 C and we would have that new record for November 18," said Coulson.
The unusually mild fall season has continued into November but Coulson says there'll be a sharp return to seasonal conditions over the weekend.
Strong winds will develop Saturday evening behind a powerful cold front.
A high of 4 C (39 F) is forecast Sunday with the chance of showers and snow showers into Monday.
Significant snowfall is expected in parts of northwestern Ontario.