The Great Lakes Frozen, Canada–United States Border, North America

Climate
The Great Lakes have a humid continental climate, Köppen climate classification Dfa (in southern areas) and Dfb (in northern parts) with varying influences from air masses from other regions including dry, cold Arctic systems, mild Pacific air masses from the West, and warm, wet tropical systems from the south and the Gulf of Mexico. The lakes themselves also have a moderating impact on the climate, they can also increase precipitation totals and produce lake-effect snowfall.
• Lake effect
The most well known winter effect of the Great Lakes on weather there is the lake effect, sometimes very localized. Even late in winter lakes often have no icepack in the middle. The prevailing winds from the west pick up the slightly warmer air and moisture from the lake surface, in relation to the cold surface winds above. As the slightly warmer, moist air passes over the colder land surface, the moisture often produces concentrated, heavy snowfall that sets up in bands or "streamers". This is similar to the effect of warmer air dropping snow as it passes over mountain ranges. During freezing weather with high winds, the "snow belts" receive regular snow fall from this localized weather pattern, especially along its eastern shore. Snow belts are found in Wisconsin, Michigan, Ohio, Pennsylvania, Ontario, and New York.