Historical Ice Breakup Dates for Chequamegon Bay, Lake Superior, 1911 to 2021 (ver. 4.0, June 2021)

Note: this data release has been superseded by version 5.0, available here: https://doi.org/10.5066/F7HT2NNP Ice breakup dates of Chequamegon Bay, Lake Superior from 1911 to 2021 were compiled by Lori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 northeast of a line straight across Chequamegon Bay out from Ellis Avenue (State highway 13). Another way ice breakup was determined has been if you could drive a boat from the outlet of Fish Creek to Houghton Point. The ice may move back and forth over that line but the ice is breaking up, moving and melting from that [...]