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Chicago Weather Center

Ask Tom why: Over a typical winter season, are there more days with snow cover or without?

January 26, 2012

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Dear Tom,

Over a typical winter season, are there more days with snow cover or without?

—John Glaenzer, Woodridge

Dear John,

Chicago definitely has more days with bare ground than with snow cover. An in-house study conducted with the help of Chicago climatologist Frank Wachowski determined that Chicago is covered by at least 1 inch of snow on 43 days during a typical snow season. With the bulk of the city's accumulating snow falling during the 150-day period from mid-November to mid-April, the city is under a snow cover less than 30 percent of the time. Checking records back to the winter of 1884-85, days of snow cover in Chicago have varied considerably, ranging from as few as eight days in the winter of 1948-49 to as many as 100 during the city's benchmark snow winter of 1978-79 when snow covered the ground from Nov. 26 to March 5.