On average, the first frost in London usually arrives in the first week of October, but an Environment Canada advisory has already been issued.

Environment Canada has issued frost advisories for much of southwestern Ontario as temperatures near or below zero will result in overnight frost.

Montreal could see between 15 and 20 centimetres of snow on Sunday.

More freezing rain and high winds could affect commutes from Prince Edward County to Kingston on Thursday and Friday.

The weather agency issued a special weather statement calling for more rain and isolated showers for Toronto, as well as Vaughan, Richmond Hill, Markham, Mississauga and Brampton.

Environment Canada has issued a special weather statement for a large portion of the region, including Hamilton, Waterloo and London.