Ottawa River at Grenville
| Monthly and Annual Mean Water Levels in Metres | Annual Extremes | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual Means | Daily Maximum | Daily Minimum | |
| 1933 | 39.93 | 39.68 | 39.57 | 41.53 | 41.60 | 40.37 | 39.64 | 39.47 | 39.17 | 39.02 | 39.13 | 39.15 | 39.85 | 42.30 | 38.88 | |
| 1934 | 39.09 | 39.08 | 39.16 | 41.11 | 41.86 | 40.58 | 39.91 | 39.29 | 39.26 | 39.47 | 39.42 | 39.67 | 39.83 | 42.44 | 38.87 | |
| 1935 | 39.51 | 39.40 | 39.78 | 40.48 | 40.41 | 39.91 | 39.97 | 39.55 | 39.36 | 39.33 | 39.55 | 39.44 | 39.73 | 40.95 | 39.20 | |
| 1936 | 39.40 | 39.37 | 40.20 | 40.96 | 42.23 | 41.02 | 39.71 | 39.31 | 39.30 | 39.73 | 40.06 | 39.58 | 40.07 | 42.94 | 39.10 | |
| 1937 | 40.07 | 39.93 | 40.05 | 40.78 | 41.35 | 40.14 | 39.51 | 39.40 | 39.29 | 39.55 | 40.37 | 40.00 | 40.04 | 41.84 | 39.10 | |
| 1938 | 39.61 | 39.64 | 40.27 | 41.73 | 41.42 | 40.26 | 39.51 | 39.38 | 39.43 | 39.56 | 39.47 | 39.43 | 39.97 | 42.37 | 39.19 | |
| 1939 | 39.40 | 39.41 | 39.44 | 40.33 | 41.62 | 40.73 | 40.10 | 39.91 | 39.45 | 39.52 | 39.68 | 39.47 | 39.92 | 41.98 | 39.21 | |
| 1940 | 39.32 | 39.26 | 39.29 | 40.33 | 40.89 | 41.10 | 40.22 | 39.51 | 39.53 | 39.37 | 39.54 | 39.59 | 39.83 | 41.65 | 39.11 | |
| 1941 | 39.59 | 39.54 | 39.55 | 40.91 | 40.50 | 39.67 | 39.58 | 39.48 | 39.53 | 39.99 | 40.52 | 40.15 | 39.92 | 42.14 | 39.24 | |
| 1942 | 39.86 | 39.82 | 40.08 | 41.03 | 40.91 | 40.45 | 39.58 | 39.40 | 39.30 | 39.29 | 39.50 | 39.37 | 39.88 | 41.66 | 39.03 | |
| 1943 | 39.45 | 39.52 | 39.77 | 40.64 | 42.10 | 41.17 | 40.04 | 39.55 | 39.64 | 39.51 | 39.68 | 39.55 | 40.05 | 42.99 | 39.25 | |
| 1944 | 39.49 | 39.37 | 39.51 | 39.85 | 40.47 | 39.64 | 39.37 | 39.26 | 39.26 | 39.35 | 39.38 | 39.39 | 39.53 | 41.04 | 39.01 | |
| 1945 | 39.36 | 39.28 | 40.03 | 40.83 | 40.73 | 40.68 | 39.58 | 39.26 | 39.34 | 39.59 | 39.69 | 39.51 | 39.82 | 41.89 | 39.12 | |
| 1946 | 39.65 | 39.64 | 40.24 | 40.45 | 40.19 | 40.22 | 39.47 | 39.32 | 39.28 | 39.44 | 39.66 | 39.85 | 39.79 | 40.93 | 39.12 | |
| 1947 | 39.77 | 39.81 | 39.80 | 41.43 | 42.69 | 42.48 | 40.59 | 39.71 | 39.49 | 39.50 | 39.46 | 39.45 | 40.35 | 43.15 | 39.22 | |
| 1948 | 39.40 | 39.35 | 39.81 | 40.72 | 40.46 | 39.94 | 39.49 | 39.36 | 39.26 | 39.19 | 39.20 | 39.34 | 39.63 | 41.07 | 38.99 | |
| 1949 | 39.44 | 39.51 | 39.72 | 41.27 | 40.78 | 40.00 | 39.92 | 39.33 | 39.33 | 39.35 | 39.35 | 39.53 | 39.79 | 41.69 | 39.07 | |
| 1950 | 39.73 | 39.61 | 39.56 | 40.66 | 40.65 | 40.17 | 39.68 | 39.43 | 39.43 | 39.39 | 39.69 | 39.84 | 39.82 | 41.21 | 39.17 | |
| 1951 | 39.80 | 39.77 | 40.19 | 42.34 | 40.95 | 39.85 | 39.95 | 39.51 | 39.54 | 39.97 | 40.72 | 40.40 | 40.25 | 43.20 | 39.28 | |
| 1952 | 40.15 | 40.06 | 40.04 | 41.20 | 41.09 | 40.47 | 39.83 | 39.86 | 39.58 | 39.62 | 39.54 | 39.89 | 40.11 | 41.82 | 39.33 | |
| 1953 | 39.88 | 39.96 | 40.44 | 41.33 | 40.31 | 39.64 | 39.43 | 39.28 | 39.18 | 39.27 | 39.25 | 39.31 | 39.77 | 41.88 | 39.01 | |
| 1954 | 39.36 | 39.42 | 39.93 | 41.05 | 40.47 | 40.42 | 39.89 | 39.55 | 39.63 | 40.47 | 40.46 | 40.24 | 40.08 | 41.75 | 39.19 | |
| 1955 | 40.10 | 39.91 | 40.00 | 41.53 | 40.28 | 39.63 | 39.35 | 39.13 | 39.14 | 39.34 | 40.07 | 39.82 | 39.86 | 42.22 | 38.91 | |
| 1956 | 39.65 | 39.57 | 39.53 | 40.57 | 40.74 | 40.33 | 39.88 | 39.77 | 40.08 | 40.16 | 39.82 | 39.81 | 39.99 | 41.25 | 39.34 | |
| 1957 | 39.79 | 39.79 | 39.94 | 40.06 | 40.04 | 39.75 | 40.64 | 39.58 | 39.69 | 39.91 | 40.29 | 40.34 | 39.99 | 41.33 | 39.15 | |
| 1958 | 40.17 | 40.06 | 40.18 | 40.69 | 39.87 | 39.74 | 39.73 | 39.47 | 39.63 | 39.87 | 40.04 | 39.88 | 39.94 | 41.01 | 39.26 | |
| 1959 | 39.77 | 39.71 | 39.61 | 40.71 | 40.46 | 39.73 | 39.37 | 39.28 | 39.48 | 39.62 | 40.16 | 40.20 | 39.84 | 41.24 | 39.08 | |
| 1960 | 39.99 | 39.98 | 39.92 | 41.44 | 41.93 | 40.17 | 40.36 | 40.01 | 39.64 | 39.62 | 39.53 | 39.46 | 40.17 | 42.50 | 39.26 | |
| 1961 | 39.44 | 39.32 | 39.39 | 39.90 | 40.02 | 39.65 | 39.60 | 39.49 | 39.49 | 39.52 | 39.40 | 39.58 | 39.57 | 40.23 | 39.11 | |
| 1962 | 39.62 | 39.67 | --- | --- | 40.37 | 39.66 | 39.13 | 39.12 | 39.23 | 39.39 | 39.74 | 40.03 | 39.62 | 40.82 | 38.94 | |
| 1963 | 40.09 | 40.03 | 40.06 | 40.48 | 40.18 | 40.28 | 40.53 | 40.73 | 41.09 | 41.08 | 41.08 | 41.16 | 40.57 | 41.24 | 39.83 | |
| 1964 | 41.19 | 41.18 | 41.21 | 41.28 | 41.27 | 41.20 | 41.07 | 41.09 | 41.12 | 41.14 | 41.14 | 41.13 | 41.17 | 41.55 | 40.86 | |
| 1965 | 41.18 | 41.22 | 41.16 | 41.26 | 41.39 | 41.21 | 41.17 | 41.18 | 41.21 | 41.42 | 41.32 | 41.32 | 41.25 | 41.53 | 40.94 | |
| 1966 | 41.27 | 41.25 | 41.39 | 41.33 | 41.24 | 41.25 | 41.13 | 41.17 | 41.13 | 41.16 | 41.22 | 41.60 | 41.26 | 41.99 | 41.01 | |
| 1967 | 41.48 | 41.28 | 41.09 | 41.13 | 41.18 | 41.18 | 41.28 | 41.20 | 41.21 | 41.25 | 41.21 | 41.31 | 41.23 | 41.77 | 40.88 | |
| 1968 | 41.26 | 41.22 | 41.15 | 41.05 | 41.22 | 41.20 | 41.22 | 41.17 | 41.16 | 41.16 | 41.16 | 41.18 | 41.18 | 41.41 | 40.77 | |
| 1969 | 41.27 | 41.24 | 41.19 | 41.17 | 40.90 | 41.28 | 41.21 | 41.21 | 41.18 | 41.19 | 41.25 | 41.29 | 41.20 | 41.43 | 40.66 | |
| 1970 | 41.24 | 41.24 | 41.21 | 41.06 | 40.96 | 41.11 | 41.18 | 41.20 | 41.17 | 41.19 | 41.20 | 41.21 | 41.16 | 41.36 | 40.61 | |
| 1971 | 41.17 | 41.18 | 41.20 | 41.17 | 41.18 | 41.19 | 41.16 | 41.15 | 41.13 | 41.13 | 41.13 | 41.18 | 41.16 | 41.42 | 40.84 | |
| 1972 | 41.19 | 41.15 | 41.18 | 41.13 | 41.43 | 41.36 | 41.34 | 41.28 | 41.25 | 41.25 | 41.34 | 41.35 | 41.27 | 41.67 | 40.95 | |
| 1973 | 41.31 | 41.32 | 41.36 | 41.58 | 41.58 | 41.39 | 41.32 | 41.21 | 41.16 | 41.20 | 41.15 | 41.29 | 41.32 | 41.84 | 40.68 | |
| 1974 | 41.22 | 41.21 | 41.35 | 41.53 | 42.12 | 41.64 | 41.17 | 41.15 | 41.20 | 41.34 | 41.38 | 41.41 | 41.39 | 42.67 | 40.66 | |
| 1975 | 41.43 | 41.42 | 41.34 | 41.39 | 41.36 | 41.28 | 41.17 | 41.23 | 41.22 | 41.28 | 41.29 | 41.36 | 41.32 | 41.84 | 40.85 | |
| 1976 | 41.19 | 41.41 | 41.21 | 41.67 | 41.41 | 41.30 | 41.28 | 41.29 | 41.34 | 41.32 | 41.25 | 41.41 | 41.34 | 42.70 | 40.67 | |
| 1977 | 41.37 | 41.31 | 41.29 | 41.24 | 41.27 | 41.20 | 41.22 | 41.21 | 41.11 | 41.14 | --- | 41.36 | 41.24 | 41.71 | 40.60 | |
| 1978 | 41.34 | 41.31 | 41.18 | 41.26 | 41.24 | 41.24 | 41.18 | 41.15 | 41.14 | 41.18 | 41.11 | 41.14 | 41.21 | 41.53 | 40.84 | |
| 1979 | 41.15 | 41.12 | 41.24 | 41.23 | 41.49 | --- | 41.20 | 41.20 | 41.17 | 41.23 | 41.30 | 41.35 | 41.24 | 42.07 | 40.92 | |
| 1980 | 41.32 | 41.24 | 41.37 | 41.33 | 41.20 | 41.19 | 41.19 | 41.18 | 41.15 | 41.21 | 41.00 | 41.32 | 41.23 | 41.78 | 40.59 | |
| 1981 | 41.27 | 41.42 | 41.16 | 41.32 | 41.33 | 41.41 | 41.24 | 41.19 | 41.20 | 41.24 | 41.26 | 41.22 | 41.27 | 41.89 | 40.67 | |
| 1982 | 41.18 | 41.20 | 41.23 | 41.28 | 41.20 | 41.20 | 41.17 | 41.16 | 41.16 | 41.17 | 41.20 | 41.38 | 41.21 | 41.64 | 41.00 | |
| 1983 | 41.44 | 41.35 | 41.34 | 41.32 | 41.47 | 41.26 | 41.18 | 41.17 | 41.15 | 41.15 | 41.14 | 41.24 | 41.27 | 42.03 | 40.64 | |
| 1984 | 41.21 | 41.28 | 41.25 | 41.38 | 41.27 | 41.35 | 41.26 | 41.20 | 41.18 | 41.17 | 41.22 | 41.31 | 41.26 | 41.59 | 40.95 | |
| 1985 | 41.39 | 41.38 | 41.36 | 41.35 | 41.32 | 41.21 | 41.20 | 41.22 | 41.17 | 41.17 | 41.15 | 41.20 | 41.26 | 41.67 | 40.95 | |
| 1986 | 41.18 | 41.15 | 41.18 | 41.31 | 41.37 | 41.28 | 41.20 | 41.17 | 41.22 | 41.24 | 41.22 | 41.23 | 41.23 | 41.66 | 40.90 | |
| 1987 | 41.22 | 41.20 | 41.23 | 41.26 | 41.17 | 41.18 | 41.17 | 41.16 | 41.15 | 41.17 | 41.17 | 41.21 | 41.19 | 41.65 | 41.00 | |
| 1988 | 41.24 | 41.27 | 41.19 | 41.26 | 41.28 | 41.19 | 41.17 | 41.20 | 41.20 | 41.33 | 41.42 | 41.35 | 41.26 | 41.57 | 40.97 | |
| 1989 | 41.32 | 41.32 | 41.27 | 41.32 | 41.42 | 41.35 | 41.17 | 41.14 | 41.17 | 41.15 | 41.24 | 41.25 | 41.26 | 41.68 | 40.99 | |
| 1990 | 41.31 | 41.31 | 41.34 | 41.38 | 41.31 | 41.22 | 41.21 | 41.17 | 41.16 | 41.25 | 41.28 | 41.42 | 41.28 | 41.59 | 41.05 | |
| 1991 | 41.37 | 41.39 | 41.37 | 41.42 | 41.20 | 41.18 | 41.15 | 41.14 | 41.14 | 41.16 | 41.19 | 41.27 | 41.25 | 41.85 | 41.03 | |
| 1992 | 41.28 | 41.28 | 41.27 | 41.37 | 41.27 | 41.18 | 41.18 | 41.17 | 41.21 | 41.25 | 41.38 | 41.34 | 41.26 | 41.51 | 41.04 | |
| 1993 | 41.35 | 41.29 | 41.23 | 41.38 | 41.23 | 41.25 | 41.17 | 41.16 | 41.16 | 41.27 | 41.32 | 41.30 | 41.26 | 41.57 | 41.03 | |
| 1994 | 41.27 | 41.33 | 41.30 | 41.18 | 41.36 | 41.30 | 41.30 | 41.24 | 41.17 | 41.16 | 41.22 | 41.23 | 41.25 | 41.56 | 40.81 | |
| 1995 | 41.39 | 41.58 | 41.46 | 41.21 | 41.32 | 41.31 | 41.16 | 41.16 | 41.14 | 41.15 | 41.24 | 41.28 | 41.28 | 41.85 | 41.11 | |
| 1996 | 41.34 | 41.38 | 41.32 | 41.30 | 41.27 | 41.28 | 41.23 | 41.20 | 41.17 | 41.18 | 41.21 | 41.24 | 41.26 | 41.59 | 41.00 | |
| 1997 | 41.29 | 41.37 | 41.39 | 41.24 | 41.48 | 41.28 | 41.22 | 41.18 | 41.17 | 41.18 | 41.21 | 41.20 | 41.27 | 41.85 | 40.94 | |
| 1998 | 41.23 | 41.25 | 41.31 | 41.45 | 41.21 | 41.18 | 41.18 | 41.15 | 41.14 | 41.15 | 41.15 | 41.20 | 41.21 | 42.06 | 41.04 | |
| 1999 | 41.27 | 41.32 | 41.31 | 41.22 | 41.21 | 41.25 | 41.23 | 41.19 | 41.18 | 41.26 | --- | --- | --- | 41.49 | 40.86 | |
| 2000 | 41.31 | 41.29 | 41.07 | 41.30 | 41.40 | 41.30 | 41.26 | 41.23 | 41.21 | 41.18 | 41.20 | 41.19 | 41.24 | 41.61 | 40.55 | |
| 2001 | 41.23 | 41.27 | 41.24 | 41.20 | 41.28 | 41.24 | 41.19 | 41.18 | 41.18 | 41.28 | 41.37 | 41.40 | 41.25 | 41.48 | 40.91 | |
| 2002 | 41.40 | 41.32 | 41.36 | 41.29 | 41.48 | 41.45 | 41.26 | 41.16 | 41.14 | 41.13 | 41.13 | 41.14 | 41.27 | 41.77 | 40.93 | |
| 2003 | 41.13 | 41.12 | 41.19 | 41.31 | 41.24 | 41.22 | 41.17 | 41.21 | 41.16 | 41.24 | 41.45 | 41.64 | 41.26 | 41.94 | 41.03 | |
| 2004 | 41.69 | 41.53 | 41.45 | 41.46 | 41.40 | 41.26 | 41.22 | 41.11 | 41.14 | 41.11 | 41.11 | 41.13 | 41.30 | 41.89 | 40.96 | |
| 2005 | 41.22 | 41.17 | 41.10 | 41.41 | 41.28 | 41.21 | 41.16 | 41.14 | 41.10 | 41.19 | 41.17 | --- | 41.20 | 41.55 | 40.94 | |
| 2006 | 41.44 | 41.52 | 41.43 | 41.36 | 41.44 | 41.34 | 41.25 | 41.20 | 41.18 | 41.29 | 41.40 | 41.41 | 41.36 | 41.82 | 41.17 | |
| 2007 | 41.30 | 41.45 | 41.46 | 41.34 | 41.28 | 41.35 | 41.21 | 41.19 | 41.18 | 41.16 | 41.15 | 41.19 | 41.27 | 41.57 | 41.07 | |
| 2008 | 41.33 | 41.41 | 41.43 | 41.71 | 41.43 | 41.39 | 41.38 | 41.34 | 41.23 | 41.21 | 41.24 | 41.33 | 41.37 | 41.95 | 41.07 | |
| 2009 | 41.43 | 41.43 | 41.46 | 41.45 | 41.47 | 41.33 | 41.30 | 41.28 | 41.19 | 41.19 | 41.29 | 41.25 | 41.34 | 41.79 | 41.10 | |
| 2010 | 41.28 | 41.28 | 41.33 | 41.24 | 41.20 | 41.19 | 41.16 | 41.16 | 41.22 | 41.28 | 41.29 | 41.52 | 41.26 | 41.76 | 40.93 | |
| 2011 | 41.38 | 41.33 | 41.40 | 41.30 | 41.44 | 41.30 | 41.25 | 41.20 | 41.20 | 41.20 | 41.19 | 41.26 | 41.29 | 41.60 | 40.98 | |
| 2012 | 41.30 | 41.33 | 41.39 | 41.32 | 41.25 | 41.21 | 41.17 | 41.16 | 41.17 | 41.21 | 41.27 | 41.28 | 41.25 | 41.56 | 41.04 | |
| 2013 | 41.31 | 41.38 | 41.34 | 41.46 | 41.54 | 41.41 | 41.22 | 41.20 | 41.20 | 41.24 | 41.40 | 41.32 | 41.34 | 41.71 | 41.13 | |
| 2014 | 41.36 | 41.35 | 41.22 | 41.43 | 41.51 | 41.32 | 41.23 | 41.22 | 41.26 | 41.33 | 41.30 | 41.31 | 41.32 | 41.67 | 41.09 | |
| 2015 | 41.49 | 41.36 | 41.29 | 41.29 | 41.31 | 41.25 | 41.18 | 41.20 | 41.21 | 41.19 | 41.23 | 41.31 | 41.28 | 41.69 | 41.08 | |
| 2016 | 41.65 | 41.80 | 41.67 | 41.53 | 41.40 | 41.28 | 41.20 | 41.19 | 41.19 | 41.19 | 41.18 | 41.24 | 41.38 | 42.10 | 41.02 | |
| 2017 | 41.29 | 41.34 | 41.44 | 41.77 | 42.00 | 41.38 | 41.31 | 41.23 | 41.23 | 41.21 | 41.32 | 41.37 | 41.41 | 42.81 | 41.10 | |
| 2018 | 41.47 | 41.42 | 41.33 | 41.26 | 41.50 | 41.28 | 41.19 | 41.15 | 41.22 | 41.28 | 41.27 | 41.30 | 41.30 | 41.78 | 41.03 | |
| 2019 | 41.32 | 41.41 | 41.34 | 41.82 | 42.33 | 41.42 | 41.17 | 41.13 | 41.14 | 41.01 | 41.21 | 41.27 | 41.38 | 42.75 | 40.88 | |
| 2020 | 41.29 | 41.26 | 41.39 | 41.44 | 41.33 | 41.27 | 41.19 | 41.22 | 41.25 | 41.31 | 41.32 | 41.36 | 41.30 | 41.80 | 40.99 | |
| 2021 | 41.66 | 41.46 | 41.35 | 41.23 | 41.18 | 41.17 | 41.23 | 41.19 | 41.21 | 41.28 | 41.24 | 41.34 | 41.29 | 41.83 | 41.03 | |
| Mean - Moyenne | 40.74 | 40.73 | 40.80 | 41.18 | 41.20 | 40.91 | 40.72 | 40.60 | 40.59 | 40.65 | 40.72 | 40.75 | 40.79 | 41.77 | 40.31 | |
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual Means | Daily Maximum | Daily Minimum | |