Portage Lake Ice Out Dates
| 1925 | May 10 | 1976 | May 2 | |||
| 1926 | May 26 | 1977 | May 12 | |||
| 1927 | April 30 | 1978 | May 12 | |||
| 1927 | May 16 | 1979 | May 3 | |||
| 1929 | May 10 | 1980 | May 4 | |||
| 1930 | May 7 | 1981 | May 1 | |||
| 1931 | May 1 | 1982 | May 9 | |||
| 1932 | May 8 | 1983 | May 1 | |||
| 1933 | May 7 | 1984 | May 8 | |||
| 1934 | May 30 | 1985 | May 6 | |||
| 1935 | May 12 | 1986 | April 28 | |||
| 1936 | May 3 | 1987 | April 20 | |||
| 1937 | May 13 | 1988 | April 28 | |||
| 1938 | April 28 | 1989 | May 5 | |||
| 1939 | May 13 | 1990 | April 30 | |||
| 1940 | May 11 | 1991 | May 5 | |||
| 1941 | May 2 | 1992 | May 11 | |||
| 1942 | May 4 | 1993 | May 3 | |||
| 1943 | May 19 | 1994 | May 12 | |||
| 1944 | May 8 | 995 | May 4 | |||
| 1945 | April 14 | 1996 | May 3 | |||
| 1946 | May 11 | 1997 | May 6 | |||
| 1947 | May 18 | 1998 | April 30 | |||
| 1948 | May 5 | 1999 | May 3 | |||
| 1949 | May 1 | 2000 | April 30 | |||
| 1950 | May 7 | 2001 | May 5 | |||
| 1951 | April 29 | 2002 | April 27 | |||
| 1952 | May 8 | 2003 | May 7 | |||
| 1953 | May 5 | 2004 | April 27 | |||
| 1954 | May 2 | 2005 | May 7 | |||
| 1955 | May 3 | 2006 | April 25 | |||
| 1956 | May 12 | 2007 | May 10 | |||
| 1957 | May 2 | 2008 | May 4 | |||
| 1958 | May 28 | 2009 | April 29 | |||
| 1959 | May 9 | 2010 | April 21 | |||
| 1960 | May 8 | 2011 | April 23 | |||
| 1961 | May 15 | 2012 | April 17 | |||
| 1962 | May 10 | 2013 | May 1 | |||
| 1963 | May 11 | 2014 | May 9 | |||
| 1964 | May 6 | 2015 | May 5 | |||
| 1965 | May 4 | 2016 | May7 | |||
| 1966 | May 9 | 2017 | May 5 | |||
| 1967 | May 7 | 2018 | May 8 | |||
| 1968 | May 2 | 2019 | May 6 | |||
| 1969 | May 11 | 2020 | May 8 | |||
| 1970 | May 13 | 2021 | April 16 | |||
| 1971 | May13 | 2022 | May 5 | |||
| 1972 | May 19 | 2023 | April 30 | |||
| 1973 | May 7 | 2024 | April 20 | |||
| 1973 | May 21 | |||||
| 1975 | May 15 |