[2] On October 29, Environment Canada issued severe wind warnings for the Great Lakes and St. Lawrence Valley corridor, from Southwestern Ontario as far as Quebec City.

[5] On October 30, Environment Canada issued storm surge warnings along the mouth of the St. Lawrence River, including the Gaspé Peninsula and Sept-Îles.

[10][11] On October 31, rainfall warnings were posted for all counties of New Brunswick that are not adjacent to Maine, including the cities of Saint John and Moncton, as well as Halifax and central Nova Scotia.

[17] As of early October 30, most of Southern Ontario was experiencing sustained winds of tropical storm force from Windsor to Ottawa, with gusts to 80 km/h (50 mph) or higher.

[25] The Emerald Princess, a cruise ship carrying 3,780 passengers and 1,200 crew members, sought shelter at Saguenay, Quebec, which was just north of Sandy's northern edge and has a naturally protected harbour.