A climatological study of snowfall in the snowbelts of Michigan shows that decade-average amounts varied by a factor of 2 during the period from 1909/10 through 1980/81. The effect of Lake Michigan on total winter snowfall along its shores has been estimated. A long-term average effect of ∼ +10% is found for the Wisconsin shore south of Sheboygan, and an average of ∼ +60% for the Michigan shore, south of Hart, with a minimum effect in the 1930s and a maximum in the 1960s.