Historical Ice Breakup Dates for Chequamegon Bay, Lake Superior, 1911 to 2021 (ver. 4.0, June 2021)
Ice breakup dates of Chequamegon Bay, Lake Superior from 1911 to 2021 were compiled by Lori Evrard (USGS, GLSC, Lake Superior Biological Station, Ashland, WI).  Ice breakup date is the day in spring when winter ice cover substantially leaves a water body.  Local residents deem "ice breakup" as when the ice moves …