Canada's Lake-Effect Snow: A Guide for Ontario and Quebec

For many in Canada, particularly in Southern Ontario and Quebec, "lake-effect snow" is a term synonymous with winter. These intense, localized snowfalls are a major factor in whether or not schools are closed in cities like Toronto and Montreal.

How Does Lake-Effect Snow Work?

Lake-effect snow occurs when cold, arctic air moves over the relatively warmer waters of a large lake, like the Great Lakes. The air picks up moisture and heat from the lake, becoming unstable. As it rises and cools over land, it dumps that moisture as heavy snow in narrow bands.

Key features include:

• Intensity: Snowfall rates can exceed several inches per hour.
• Localization: One town might get a foot of snow while a neighboring town gets none.
• Wind: Strong winds often accompany these events, creating whiteout conditions.

Predicting Lake-Effect Snow Days

Because of its unpredictable nature, forecasting a snow day from lake-effect snow is challenging. Our snow day calculator is specifically designed to handle this. It analyzes wind direction, temperature differences between the air and the lake, and high-resolution forecast models to determine where and when these intense snow bands will hit, giving you a precise snow day chance for your area in Canada.