Warm lake waterOpen water, warmer than the air above it.
CloudsClouds form as the warmed, moist air rises. They grow as the air crosses the lake.
Snow bandA narrow band of heavy snow.
WindThe wind carries the cold air across the lake. Its direction decides which shore gets the snow.
Where the snow falls 5
Heat and moistureThe lake warms and moistens the lowest air. That air then rises.
FetchThe distance the wind travels over open water. A longer fetch can bring more snow.
Downwind shoreThe shore the wind reaches after the lake.
SnowbeltLand downwind of the lake where lake effect snow falls often.
HillsHigher ground lifts the air and adds to the snow.
How this list was compiled: Every name checked on 2026-10-03 in two of these. (1) US National Weather Service, What is a Lake Effect Snow?, https://www.weather.gov/safety/winter-lake-effect-snow (cold air crossing the open, relatively warm water; warmth and moisture passing into the lowest air; the air rising; clouds growing into a narrow band of snow; wind direction). (2) Wikipedia, Lake-effect snow, https://en.wikipedia.org/wiki/Lake-effect_snow (the same steps; fetch; the downwind shores; snowbelts; higher ground on the downwind shore; western Michigan and the Upper Peninsula). (3) Val L. Eichenlaub, Weather and Climate of the Great Lakes Region (1979), https://archive.org/details/weatherclimateof00eich (fetch as the length of wind flow over the lake surface; the downwind shores where lake-effect snows are frequent). (4) Rauber, Walsh and Charlevoix, Severe and Hazardous Weather (2014), https://archive.org/details/severehazardousw0000robe (hills add lifting along the downwind shores and increase the snowfall). (5) The Great Lake Erie: A Reference Text for Educators and Communicators (1993), ERIC document ED361227, https://archive.org/details/ERIC_ED361227 (downwind or lee shores; a snowbelt on the eastern and southeastern shores). (6) Val L. Eichenlaub and others, The Climatic Atlas of Michigan (1990), https://archive.org/details/climaticatlasofm0000eich (snowbelt areas of the Upper Peninsula and the northern Lower Peninsula, along the downwind shores of the lakes). Sources 3 to 6 were read by full-text search on the Internet Archive. Licence: own work
The drawing: Drawn for this site on 2026-10-03 from plain geometry. Own original drawing; nothing is traced or copied. Licence: own work
How it works
This lake effect snow labeled diagram cuts through a lake from the upwind shore to the downwind shore. It shows no real lake; in Michigan it could be Lake Michigan, with the snowbelt on its eastern shore.
Read the full guide
Over the lake
Read from left to right, the way the wind blows. Cold air moves out over warm lake water. Heat and moisture pass up into the lowest air, which rises, and clouds form and grow as the air crosses. The distance the wind travels over open water is the fetch.
On the far side
The clouds grow into a narrow snow band that reaches the downwind shore. The land behind that shore, where this snow falls often, is the snowbelt. Hills there lift the air again and add to the snow.
Questions and answers
What causes lake effect snow?
Cold air moves across a lake's open, warmer water. Warmth and moisture pass into the lowest air, which rises. Clouds form and grow into a narrow band that drops heavy snow on and near the downwind shore.
What is fetch in lake effect snow?
Fetch is the distance the wind travels over open water. With a longer fetch the air has more time to take up heat and moisture from the lake, so it can produce more snow.
What is a snowbelt?
A snowbelt is an area downwind of a large lake where lake effect snow falls often. Around the Great Lakes the snowbelts lie mostly along the eastern and southern shores.
Why does Michigan get lake effect snow?
Winds that cross Lake Superior and Lake Michigan take up heat and moisture and drop snow on the downwind shores. The Upper Peninsula and western Michigan lie on those shores, so both get heavy lake effect snow.