Historical Ice Breakup Dates for Chequamegon Bay, Lake Superior, 1911 to 2019 (ver. 2.0, May 2019)

Note: there is a updated version of this data release, available here: https://doi.org/10.5066/F7HT2NNP. Ice breakup dates of Chequamegon Bay, Lake Superior from 1911 to 2019. 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 date on. Ellis Avenue ends on a bluff (46.5925 degrees North, 90.8827 degrees West) that provides [...]