Historical Monthly and Yearly Mean Water Level Graphs 1918-2013

Lake Superior monthly mean water levels in metres referred to IGLD 1985

Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Yearly
Average
Minimum
Monthly
Maximum
Monthly
Range
1918 183.25 183.20 183.17 183.14 183.22 183.34 183.40 183.43 183.45 183.44 183.46 183.44 183.33 183.14 183.46 0.32
1919 183.38 183.32 183.28 183.31 183.38 183.45 183.48 183.47 183.46 183.42 183.43 183.39 183.40 183.28 183.48 0.20
1920 183.29 183.27 183.28 183.36 183.43 183.52 183.58 183.60 183.54 183.50 183.43 183.36 183.43 183.27 183.60 0.33
1921 183.31 183.22 183.18 183.23 183.35 183.44 183.48 183.50 183.50 183.44 183.35 183.27 183.36 183.18 183.50 0.32
1922 183.17 183.11 183.09 183.15 183.29 183.36 183.45 183.50 183.52 183.45 183.39 183.31 183.32 183.09 183.52 0.43
1923 183.23 183.15 183.12 183.11 183.18 183.21 183.27 183.30 183.32 183.30 183.28 183.22 183.22 183.11 183.32 0.21
1924 183.15 183.07 183.01 183.02 183.05 183.09 183.12 183.20 183.26 183.28 183.20 183.11 183.13 183.01 183.28 0.27
1925 183.02 182.96 182.93 182.94 182.98 183.06 183.12 183.16 183.15 183.10 183.01 182.92 183.03 182.92 183.16 0.24
1926 182.83 182.76 182.74 182.72 182.76 182.85 182.96 183.02 183.12 183.19 183.18 183.19 182.94 182.72 183.19 0.47
1927 183.12 183.08 183.07 183.12 183.27 183.39 183.50 183.52 183.50 183.49 183.44 183.38 183.32 183.07 183.52 0.45
1928 183.31 183.24 183.20 183.25 183.36 183.44 183.56 183.62 183.69 183.74 183.68 183.57 183.47 183.20 183.74 0.54
1929 183.46 183.42 183.44 183.47 183.47 183.51 183.57 183.56 183.56 183.55 183.52 183.44 183.50 183.42 183.57 0.15
1930 183.37 183.34 183.30 183.28 183.39 183.48 183.58 183.58 183.53 183.53 183.47 183.42 183.44 183.28 183.58 0.30
1931 183.33 183.25 183.18 183.16 183.22 183.30 183.39 183.41 183.40 183.42 183.43 183.42 183.33 183.16 183.43 0.27
1932 183.37 183.34 183.30 183.28 183.38 183.45 183.52 183.58 183.58 183.48 183.45 183.38 183.43 183.28 183.58 0.30
1933 183.32 183.28 183.24 183.28 183.43 183.52 183.56 183.57 183.57 183.57 183.53 183.47 183.44 183.24 183.57 0.33
1934 183.42 183.37 183.34 183.36 183.47 183.55 183.58 183.55 183.58 183.61 183.59 183.55 183.50 183.34 183.61 0.27
1935 183.47 183.42 183.40 183.40 183.47 183.53 183.62 183.65 183.63 183.57 183.52 183.44 183.51 183.40 183.65 0.25
1936 183.39 183.34 183.33 183.35 183.51 183.59 183.59 183.57 183.57 183.51 183.43 183.33 183.46 183.33 183.59 0.26
1937 183.31 183.29 183.27 183.27 183.42 183.50 183.54 183.60 183.61 183.58 183.57 183.49 183.45 183.27 183.61 0.34
1938 183.42 183.38 183.35 183.43 183.62 183.72 183.73 183.72 183.69 183.61 183.57 183.49 183.56 183.35 183.73 0.38
1939 183.46 183.43 183.40 183.42 183.52 183.66 183.75 183.75 183.71 183.62 183.51 183.43 183.56 183.40 183.75 0.35
1940 183.33 183.25 183.18 183.16 183.28 183.45 183.53 183.55 183.53 183.48 183.46 183.39 183.38 183.16 183.55 0.39
1941 183.32 183.25 183.18 183.21 183.34 183.44 183.49 183.52 183.61 183.71 183.66 183.57 183.44 183.18 183.71 0.53
1942 183.48 183.41 183.38 183.38 183.51 183.59 183.61 183.62 183.65 183.64 183.65 183.60 183.54 183.38 183.65 0.27
1943 183.53 183.49 183.45 183.44 183.56 183.73 183.80 183.80 183.75 183.67 183.59 183.48 183.61 183.44 183.80 0.36
1944 183.36 183.28 183.24 183.23 183.38 183.55 183.66 183.76 183.78 183.70 183.62 183.52 183.51 183.23 183.78 0.55
1945 183.42 183.38 183.38 183.51 183.53 183.56 183.63 183.65 183.70 183.64 183.58 183.52 183.54 183.38 183.70 0.32
1946 183.45 183.40 183.36 183.42 183.45 183.52 183.60 183.61 183.62 183.62 183.63 183.57 183.52 183.36 183.63 0.27
1947 183.47 183.38 183.32 183.36 183.49 183.67 183.75 183.74 183.73 183.66 183.57 183.46 183.55 183.32 183.75 0.43
1948 183.37 183.27 183.21 183.27 183.40 183.42 183.46 183.51 183.53 183.45 183.43 183.40 183.39 183.21 183.53 0.32
1949 183.33 183.28 183.22 183.24 183.36 183.44 183.57 183.64 183.60 183.60 183.56 183.48 183.44 183.22 183.64 0.42
1950 183.42 183.37 183.33 183.37 183.57 183.74 183.82 183.86 183.83 183.82 183.77 183.69 183.63 183.33 183.86 0.53
1951 183.57 183.51 183.52 183.59 183.71 183.75 183.80 183.80 183.83 183.84 183.79 183.70 183.70 183.51 183.84 0.33
1952 183.63 183.56 183.50 183.52 183.58 183.62 183.77 183.86 183.82 183.67 183.52 183.46 183.63 183.46 183.86 0.40
1953 183.37 183.32 183.28 183.33 183.40 183.57 183.69 183.72 183.67 183.57 183.45 183.40 183.48 183.28 183.72 0.44
1954 183.31 183.25 183.20 183.22 183.44 183.57 183.62 183.59 183.52 183.47 183.41 183.33 183.41 183.20 183.62 0.42
1955 183.24 183.17 183.16 183.21 183.30 183.37 183.39 183.47 183.45 183.49 183.47 183.40 183.34 183.16 183.49 0.33
1956 183.31 183.25 183.16 183.16 183.22 183.32 183.43 183.48 183.48 183.42 183.37 183.30 183.32 183.16 183.48 0.32
1957 183.21 183.13 183.12 183.14 183.26 183.35 183.46 183.48 183.48 183.43 183.40 183.34 183.32 183.12 183.48 0.36
1958 183.26 183.21 183.16 183.14 183.18 183.24 183.36 183.40 183.47 183.44 183.43 183.37 183.30 183.14 183.47 0.33
1959 183.28 183.21 183.19 183.18 183.29 183.40 183.46 183.52 183.63 183.64 183.56 183.44 183.40 183.18 183.64 0.46
1960 183.37 183.30 183.22 183.24 183.47 183.56 183.56 183.55 183.53 183.45 183.40 183.34 183.42 183.22 183.56 0.34
1961 183.24 183.18 183.17 183.19 183.29 183.36 183.38 183.38 183.42 183.41 183.39 183.33 183.31 183.17 183.42 0.25
1962 183.24 183.18 183.15 183.15 183.25 183.35 183.38 183.41 183.47 183.45 183.35 183.28 183.30 183.15 183.47 0.32
1963 183.19 183.14 183.11 183.18 183.24 183.35 183.41 183.44 183.44 183.41 183.36 183.29 183.30 183.11 183.44 0.33
1964 183.21 183.15 183.09 183.09 183.30 183.41 183.48 183.51 183.54 183.51 183.45 183.36 183.34 183.09 183.54 0.45
1965 183.28 183.21 183.16 183.18 183.31 183.38 183.41 183.44 183.43 183.45 183.41 183.39 183.34 183.16 183.45 0.29
1966 183.33 183.27 183.26 183.28 183.36 183.47 183.49 183.54 183.52 183.47 183.42 183.37 183.40 183.26 183.54 0.28
1967 183.31 183.26 183.21 183.29 183.39 183.45 183.50 183.53 183.49 183.44 183.41 183.34 183.38 183.21 183.53 0.32
1968 183.26 183.19 183.14 183.23 183.33 183.49 183.63 183.72 183.79 183.78 183.71 183.61 183.49 183.14 183.79 0.65
1969 183.56 183.53 183.46 183.46 183.55 183.57 183.58 183.59 183.54 183.50 183.44 183.35 183.51 183.35 183.59 0.24
1970 183.30 183.24 183.19 183.18 183.36 183.50 183.59 183.61 183.60 183.59 183.65 183.60 183.45 183.18 183.65 0.47
1971 183.51 183.45 183.44 183.47 183.56 183.66 183.70 183.70 183.67 183.65 183.62 183.56 183.58 183.44 183.70 0.26
1972 183.48 183.42 183.42 183.43 183.55 183.58 183.60 183.68 183.71 183.68 183.60 183.49 183.55 183.42 183.71 0.29
1973 183.43 183.36 183.38 183.43 183.58 183.67 183.73 183.80 183.80 183.74 183.65 183.58 183.60 183.36 183.80 0.44
1974 183.50 183.44 183.39 183.40 183.52 183.63 183.72 183.77 183.79 183.77 183.76 183.69 183.62 183.39 183.79 0.40
1975 183.62 183.57 183.51 183.46 183.55 183.62 183.69 183.68 183.66 183.60 183.59 183.58 183.59 183.46 183.69 0.23
1976 183.49 183.42 183.40 183.49 183.57 183.59 183.63 183.62 183.55 183.46 183.35 183.24 183.48 183.24 183.63 0.39
1977 183.16 183.10 183.13 183.20 183.27 183.31 183.40 183.44 183.58 183.65 183.62 183.54 183.37 183.10 183.65 0.55
1978 183.48 183.36 183.31 183.30 183.35 183.44 183.52 183.57 183.61 183.55 183.43 183.34 183.44 183.30 183.61 0.31
1979 183.25 183.21 183.24 183.31 183.50 183.65 183.68 183.68 183.67 183.61 183.60 183.53 183.49 183.21 183.68 0.47
1980 183.47 183.40 183.33 183.35 183.39 183.43 183.46 183.49 183.55 183.53 183.46 183.37 183.44 183.33 183.55 0.22
1981 183.27 183.22 183.22 183.32 183.40 183.47 183.51 183.49 183.41 183.38 183.35 183.28 183.36 183.22 183.51 0.29
1982 183.23 183.16 183.13 183.19 183.35 183.41 183.50 183.57 183.58 183.65 183.67 183.61 183.42 183.13 183.67 0.54
1983 183.56 183.49 183.47 183.48 183.51 183.59 183.64 183.63 183.61 183.64 183.61 183.58 183.57 183.47 183.64 0.17
1984 183.49 183.44 183.40 183.39 183.49 183.59 183.65 183.66 183.63 183.61 183.58 183.55 183.54 183.39 183.66 0.27
1985 183.48 183.42 183.41 183.45 183.58 183.66 183.74 183.81 183.86 183.91 183.89 183.81 183.67 183.41 183.91 0.50
1986 183.70 183.63 183.61 183.68 183.74 183.76 183.81 183.84 183.81 183.79 183.75 183.67 183.73 183.61 183.84 0.23
1987 183.58 183.50 183.44 183.41 183.42 183.46 183.50 183.55 183.53 183.46 183.40 183.37 183.47 183.37 183.58 0.21
1988 183.29 183.22 183.17 183.20 183.24 183.26 183.27 183.39 183.44 183.41 183.46 183.46 183.32 183.17 183.46 0.29
1989 183.41 183.33 183.28 183.31 183.39 183.50 183.53 183.52 183.50 183.41 183.38 183.27 183.40 183.27 183.53 0.26
1990 183.19 183.13 183.09 183.08 183.18 183.25 183.35 183.36 183.38 183.39 183.38 183.31 183.26 183.08 183.39 0.31
1991 183.23 183.16 183.14 183.22 183.32 183.37 183.46 183.46 183.44 183.43 183.46 183.45 183.34 183.14 183.46 0.32
1992 183.37 183.30 183.25 183.22 183.32 183.36 183.45 183.47 183.52 183.54 183.50 183.47 183.40 183.22 183.54 0.32
1993 183.41 183.32 183.24 183.24 183.38 183.48 183.56 183.62 183.62 183.58 183.52 183.46 183.45 183.24 183.62 0.38
1994 183.39 183.32 183.28 183.30 183.40 183.46 183.53 183.56 183.59 183.56 183.50 183.42 183.44 183.28 183.59 0.31
1995 183.33 183.24 183.19 183.20 183.26 183.31 183.37 183.40 183.44 183.49 183.48 183.41 183.34 183.19 183.49 0.30
1996 183.34 183.32 183.30 183.31 183.46 183.60 183.70 183.78 183.78 183.71 183.67 183.63 183.55 183.30 183.78 0.48
1997 183.59 183.54 183.51 183.55 183.64 183.65 183.72 183.68 183.64 183.61 183.56 183.48 183.60 183.48 183.72 0.24
1998 183.40 183.34 183.29 183.35 183.34 183.39 183.41 183.38 183.33 183.26 183.21 183.19 183.32 183.19 183.41 0.22
1999 183.12 183.10 183.06 183.11 183.20 183.31 183.43 183.47 183.44 183.38 183.32 183.24 183.27 183.06 183.47 0.41
2000 183.16 183.08 183.08 183.12 183.16 183.24 183.33 183.31 183.27 183.20 183.15 183.06 183.18 183.06 183.33 0.27
2001 182.98 182.94 182.91 183.01 183.24 183.33 183.36 183.39 183.37 183.30 183.29 183.30 183.20 182.91 183.39 0.48
2002 183.22 183.14 183.11 183.14 183.26 183.31 183.36 183.40 183.42 183.44 183.36 183.26 183.29 183.11 183.44 0.33
2003 183.16 183.07 183.03 183.08 183.18 183.23 183.26 183.29 183.27 183.26 183.23 183.19 183.19 183.03 183.29 0.26
2004 183.14 183.07 183.07 183.13 183.23 183.35 183.40 183.42 183.46 183.47 183.46 183.38 183.30 183.07 183.47 0.40
2005 183.32 183.27 183.22 183.26 183.31 183.39 183.42 183.38 183.35 183.38 183.35 183.30 183.33 183.22 183.42 0.20
2006 183.24 183.18 183.12 183.16 183.24 183.30 183.31 183.30 183.20 183.13 183.04 182.98 183.18 182.98 183.31 0.33
2007 182.92 182.83 182.78 182.85 182.87 182.94 183.00 183.01 183.02 183.18 183.18 183.11 182.97 182.78 183.18 0.40
2008 183.08 183.03 182.97 183.01 183.18 183.29 183.41 183.42 183.37 183.32 183.27 183.19 183.21 182.97 183.42 0.45
2009 183.14 183.10 183.09 183.12 183.24 183.30 183.34 183.39 183.42 183.36 183.35 183.30 183.26 183.09 183.42 0.33
2010 183.21 183.14 183.09 183.08 183.08 183.13 183.19 183.20 183.22 183.19 183.14 183.07 183.15 183.07 183.22 0.15
2011 183.00 182.93 182.87 182.91 183.04 183.15 183.25 183.28 183.23 183.21 183.16 183.09 183.09 182.87 183.28 0.41
2012 183.01 182.94 182.93 183.00 183.06 183.20 183.30 183.27 183.20 183.13 183.11 183.06 183.10 182.93 183.30 0.37
2013 182.98 182.94 182.91 182.90 183.11 183.26 183.37 183.44 183.48 183.45 183.40 183.35 183.22 182.90 183.48 0.58
2014 183.29 183.24 183.23 183.27 183.47 183.60 183.66 183.67 183.70 183.71 183.67 183.60 183.51 183.23 183.71 0.48
2015 183.54 183.47 183.42 183.44 183.53 183.63 183.68 183.68 183.69 183.60 183.58 183.59 183.57 183.42 183.69 0.27
2016 183.55 183.49 183.46 183.48 183.50 183.61 183.69 183.70 183.70 183.68 183.59 183.54 183.58 183.46 183.70 0.24
2017 183.26 183.23 183.26 183.36 183.45 183.51 183.54 183.54 183.51 183.47 183.40 183.40 183.41 183.23 183.54 0.31

All-Time

Average 183.33 183.26 183.23 183.26 183.36 183.45 183.51 183.54 183.54 183.51 183.47 183.40 183.40 183.23 183.54 0.31
Minimum 182.83 182.76 182.74 182.72 182.76 182.85 182.96 183.01 183.02 183.10 183.01 182.92 182.89 182.72 183.10 0.38
Maximum 183.70 183.63 183.61 183.68 183.74 183.76 183.82 183.86 183.86 183.91 183.89 183.81 183.77 183.61 183.91 0.30

2008-2017

Average 183.23 183.17 183.14 183.16 183.28 183.38 183.46 183.48 183.48 183.45 183.41 183.35

Lake Superior water levels in metres referred to Chart Datum

2017 0.27 0.23 0.19 0.21 0.36 0.47 0.55 0.58 0.60 0.61 0.58 0.52
All-Time
Average 0.13 0.06 0.03 0.06 0.16 0.25 0.31 0.34 0.34 0.31 0.27 0.20
Minimum -0.37 -0.44 -0.46 -0.48 -0.44 -0.35 -0.24 -0.19 -0.18 -0.10 -0.19 -0.28
Maximum 0.50 0.43 0.41 0.48 0.54 0.56 0.62 0.66 0.66 0.71 0.69 0.61