Ice Out Dates on Black Oak Lake

A typical spring situation sees the south facing shoreline receiving more and more heat as the sun tracks higher in the southern sky. The ice will melt off of those south and west facing banks and the widening strip of open water along those shores. Meanwhile the overall ice sheet is hollowing out from beneath, called “honeycombing”. Though the vast majority of the lake still appears to be covered the ice is very weak. Then, if a warm gusty south wind comes up, the ice will be gone in two to three hours.

The DNR’s definition of “ice-out” is the first day that all ice is gone. The DNR wants simple and clear definitions of things like this so different observers over the decades will have the same reference making long term comparisons valid. In the Citizen Lake Monitoring Network, we are trained on the rituals of taking Secchi measurements as well as the chemistry testing of Phosphorous and Chlorophyll concentrations for this same reason.

Since ice-out is normally a rather sudden and sometimes noisy event, these dates have been recorded here since 1909. Emil Wiesse, who lived in Barber’s Bay (then called Wiesse Bay) in the current home of Caruso / Basten, recorded them through 1921, writing them on his garage wall. Janet Vineyard’s family, the Handlos’, then recorded them through 1965. Jim Lowenstine’s caretakers took over through 1997 and John Annin and Walt Bates have recorded them since then. Most often, the last ice on the lake is the south shore of Barbers Bay from Basten to Erickson. This is the most sheltered north facing shoreline on the lake. Notice that all of the early observers happen to have been located in Barbers Bay and easily looked out on that “last ice” area. This was especially helpful in the early 1900s when rowing those heavy Rhinelander rowboats was the most common means of checking the whole lake! Those early observers were therefore using the eventual DNR definition of “ice-out” without even realizing it! This gives us confidence that all our ice-out dates were recorded using the same rules and enhances the validity of comparisons over the decades.

The earliest recorded ice-out was on March 24 (2012) and the latest was on May 17 (1996). The overall average date is April 26. The raw data from which all the date averaging is drawn is available here. Also on that page are the averages for halfs, thirds and quarters of the entire list. Finally, there is a graph of all the dates. Note in the graph that there is no discernable up or down trend but that the dates are far more scattered in the last half than the first half.

The recorded dates follow:

2024: APRIL 14
2023: MAY 9
2022: MAY 10
2021: APRIL 11
2020: MAY 2
2019: MAY 6
2018: MAY 12
2017: APR 15
2016: APR 22
2015: APR 20
2014: MAY 12
2013: MAY 14
2012: MAR 24
2011: MAY 1
2010: APRIL 3
2009: APRIL 30
2008: MAY 4
2007: APRIL 23
2006: APRIL 19
2005: APRIL 19
2004: APRIL 27
2003: APRIL 29
2002: APRIL 25
2001: APRIL 25
2000: APRIL 18
1999: APRIL 16
1998: APRIL 13
1997: MAY 4
1996: MAY 17
1995: APRIL 30
1994: APRIL 24
1993: MAY 6
1992: MAY 1
1991: APRIL 23
1990: APRIL 22
1989: MAY 4
1988: APRIL 19
1987: APRIL 13
1986: APRIL 14
1985: APRIL 23
1984: APRIL 25
1983: MAY 4
1982: MAY 4
1981: APRIL 14
1980: APRIL 27
1979: MAY 9
1978: MAY 3
1977: APRIL 19
1976: APRIL 18
1975: MAY 5
1974: APRIL 29
1973: APRIL 19
1972: MAY 10
1971: APRIL 28
1970: APRIL 28
1969: APRIL 22
1968: APRIL 12
1967: APRIL 20
1966: MAY 5
1965: MAY 3
1964: APRIL 25
1963: APRIL 17
1962: APRIL 29
1961: MAY 5
1960: APRIL 24
1959: APRIL 26
1958: APRIL 23
1957: APRIL 23
1956: MAY 7
1955: APRIL 19
1954: APRIL 27
1953: APRIL 29
1952: APRIL 27
1951: MAY 2
1950: MAY 16
1949: APRIL 23
1948: APRIL 23
1947: MAY 10
1946: APRIL 15
1945: MAR 27
1944: APRIL 30
1943: MAY 4
1942: APRIL 22
1941: APRIL 17
1940: MAY 5
1939: MAY 3
1938: APRIL 15
1937: MAY 4
1936: MAY 7
1935: APRIL 27
1934: MAY 3
1933: APRIL 28
1932: APRIL 24
1931: APRIL 20
1930: APRIL 28
1929: APRIL 28
1928: APRIL 20
1927: APRIL 26
1926: APRIL 29
1925: APRIL 28
1924: APRIL 24
1923: APRIL 29
1922: APRIL 23
1921: APRIL 26
1920: APRIL 30
1919: APRIL 29
1918: MAY 1
1917: APRIL 30
1916: APRIL 27
1915: APRIL 20
1914: APRIL 26
1913: APRIL 29
1912: APRIL 28
1911: APRIL 24
1910: APRIL 1
1909: MAY 10