Country= U.S.A. Station= HENRY, IL River= ILLINOIS RIVER Area= 35074.29 Lat= 41.11 Lon= -89.35 Source= USGS PointID= 5558300 Area Units= km2 Discharge Units= m3/sec Starting Year= 1945 Ending Year= 1981 Total Years= 37 Total Usable Years= 36 Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg Annual 1945 47.73 47.86 44.61 46.39 118.1 172.91 99.64 42.22 36.45 42.6 50.07 44.47 66.09 1946 45.33 44.5 47.14 88.44 170.38 176.07 87.19 41.75 55.67 69.97 61.5 55.69 78.64 1947 43.66 45.07 58.65 89.5 299.83 228.37 112.38 51.07 51.04 65.49 62.59 50.43 96.51 1948 45.82 44.99 44.06 64.87 195.61 314.72 112.84 52.37 42.9 57 57.09 46.58 89.9 1949 43.22 47.73 56.73 85.4 225.64 187.34 68.68 38.93 39.15 51.2 53.65 46.39 78.67 1950 36.45 47.77 47.76 60.79 127.65 269.97 146.86 57.56 57.46 63 65.6 54.94 86.32 1951 46.32 54.21 54.49 116.06 271.24 267.44 152.56 80.76 52.99 64.03 61.28 51.95 106.11 1952 50.41 47.46 47.44 94.7 246.41 242.43 103 49.3 39.85 47.18 49.71 46.4 88.69 1953 53.08 46.2 46.51 61.49 115.94 319.26 163.01 55.14 43.24 48.04 55.75 50.14 88.15 1954 48.09 46.99 46.37 65.09 191.3 180.29 128.7 48.87 39.9 45.71 49.34 41.98 77.72 1955 44.9 42.37 42.25 42.92 97 213.41 109.67 40.37 36.69 44.95 54.84 62.65 69.33 1956 51.98 43.48 67.78 113.83 314.19 358.46 123.53 60.61 49.12 59.82 57.46 49.46 112.48 1957 43.07 50.76 52.39 56.63 274.32 338.91 115.52 47.19 46.87 60.49 58.13 53.48 99.81 1958 46.92 55.79 48.15 56.87 277.2 238.55 86.24 49.34 42.23 49.43 57.48 56.26 88.71 1959 49.06 46.7 46.58 66.26 101.53 240.02 86.84 41.72 51.2 69.83 63.14 50.54 76.12 1960 48.6 48.39 61.91 83.92 122.97 189.1 55.49 36.13 36.55 43.01 50.46 45.22 68.48 1961 42.58 47.38 41.23 39.5 100.07 155.05 41.83 25.43 42.1 44.49 45.47 43.96 55.76 1962 44.28 47.58 46.3 78.33 122.7 222.7 89.1 46.82 35.35 60.32 56.64 49.4 74.96 1963 39.89 66.6 43.96 51.16 159.72 270.52 104.06 46.18 51.44 52.79 57.12 45.06 82.37 1964 39.21 42.73 43.56 56.44 152.34 317.47 133.84 52.49 45.76 51.59 55.49 68.59 88.29 1965 53.68 51.85 50.08 96.37 222.04 469.21 234.59 99.49 79.43 67.38 65.07 60.48 129.14 1966 55.56 51.22 48.54 60.46 97.16 94.78 39.25 23.27 30.02 39.92 45.07 42.38 52.3 1967 43.27 40.02 39.84 41.75 160.85 338.65 135.68 43.57 38.24 65.55 59.98 49 88.03 1968 45.36 49.09 48.6 53.02 105.3 216.11 79.19 53.52 52.08 61.69 58.96 50.28 72.77 1969 53.98 44.97 52.61 123.54 263.32 212.46 90.93 40.78 40.72 55.94 50.24 47.51 89.75 1970 50.62 43.9 42.51 42.08 159.32 330.5 148.7 48.32 54.34 58.11 61.73 53.1 91.1 1971 60.08 57.6 49.76 68.93 272.75 441.46 184.7 71.6 55.64 67.64 63.85 62.81 121.4 1972 63.41 66.87 77.66 63.37 188.22 420.42 129.45 60.2 52.06 62.45 58.61 50.91 107.8 1973 48.3 46.29 46.44 51.38 103.78 114.13 53.4 29.88 39.68 45.62 61.56 50.18 57.55 1974 66.05 47.96 56.3 87.32 202.37 475.44 172.55 71.2 47.78 58.29 59.87 50.74 116.32 1975 48.62 47.67 47.34 47.87 102.75 366.59 252.3 75.57 51.65 68.88 66.73 63.54 103.29 1976 55.37 54.69 56.98 105.48 325.17 289.48 122.47 75.85 70.41 69.92 62.42 52.58 111.74 1977 48.57 50.76 45.38 41.93 46.79 89.18 44.41 28.88 35.94 47.94 47.83 52.28 48.32 1978 49.5 44.21 72.95 94.72 156.18 282.65 157.73 59.75 63.42 55.77 57.01 47.76 95.14 1979 47.51 51.43 54.72 58.06 143.6 132.63 52.41 35.22 29.88 42.66 47.88 46 61.83 1980 41.97 51.71 42.53 67.17 212.92 215.76 112.9 44.14 53.73 52.64 60.49 55.78 84.31 1981 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -9999 Avg 48.4 49.02 50.56 70.06 179.07 260.9 114.77 50.71 46.97 55.87 56.95 51.36 86.22 Std Dev 6.28 5.75 8.52 22.8 72.36 98.16 48.67 16.01 10.51 9.14 5.79 6.17 19.35