Does Lake Ontario Freeze?

Lake Ontario is also nearly all ice free, but Ontario never freezes over because of its depth. Erie is much more shallow and can regularly freeze over.

When was the last time Lake Ontario frozen?

Based on the anecdotal record, the surface of Lake Ontario completely froze over during the winters of 1829/30, 1873/74, 1892/93, 1911/12 and most recently 1933/34 (May, 2008).

How much of Lake Ontario is frozen?

Because of its great depth, the lake as a whole does not completely freeze in winter, but an ice sheet covering between 10% and 90% of the lake area typically develops, depending on the severity of the winter.