| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1923 | ----- | z | ----- | z | ----- | z | ----- | z | 81.52 | 81.90 | 93.27 | a | 88.77 | 83.37 | 71.55 | 62.00 | 52.10 | 76.81 | d | |||||||
| 1924 | 51.03 | 64.38 | 57.77 | 70.00 | 82.84 | 90.83 | 93.19 | 93.68 | 88.03 | 72.39 | 61.83 | 50.87 | 73.07 | |||||||||||||
| 1925 | 53.81 | 60.39 | 65.35 | 70.20 | 76.60 | a | 84.21 | a | 94.26 | 91.00 | 81.73 | 73.00 | 60.80 | 57.42 | 72.40 | |||||||||||
| 1926 | 54.84 | 58.96 | 67.35 | 72.20 | 80.84 | 94.30 | 95.13 | 94.90 | 86.70 | 77.90 | 67.27 | 48.03 | 74.87 | |||||||||||||
| 1927 | 53.55 | 56.82 | 62.52 | 69.93 | 79.45 | 89.13 | 96.48 | 91.52 | 84.20 | 77.16 | 65.70 | 52.19 | 73.22 | |||||||||||||
| 1928 | 55.74 | 58.62 | 66.81 | 72.97 | 82.81 | 90.87 | 96.23 | 95.00 | 90.20 | 75.55 | 62.77 | 50.35 | 74.83 | |||||||||||||
| 1929 | 52.71 | 53.79 | 64.55 | 66.79 | b | 81.19 | 86.60 | 95.13 | a | 95.00 | 85.31 | a | 81.57 | a | 67.80 | 61.26 | 74.31 | |||||||||
| 1930 | 46.90 | 62.46 | 62.63 | a | 72.30 | 69.94 | 90.63 | 94.65 | 92.42 | 83.27 | 73.42 | 63.50 | 50.71 | 71.90 | ||||||||||||
| 1931 | 53.65 | 57.46 | 67.87 | 73.60 | 83.03 | 86.80 | 100.48 | 93.81 | 83.67 | 74.32 | 57.37 | 46.74 | 73.23 | |||||||||||||
| 1932 | 46.13 | 53.03 | 66.58 | 70.00 | 77.87 | 88.27 | 95.42 | 94.35 | 89.40 | 75.39 | 67.43 | 49.68 | 72.80 | |||||||||||||
| 1933 | 45.70 | a | 49.04 | 64.00 | 68.90 | 70.26 | 89.97 | a | 100.00 | 94.16 | 88.47 | 81.06 | 63.86 | b | 50.70 | a | 72.18 | |||||||||
| 1934 | 55.35 | 59.50 | 73.48 | 78.93 | a | 82.35 | 83.63 | 94.23 | 94.23 | 86.43 | 73.07 | a | 62.37 | 50.90 | 74.54 | |||||||||||
| 1935 | 47.56 | m | 55.50 | 56.71 | 65.60 | 73.23 | 90.60 | 88.90 | 89.68 | ----- | z | 68.32 | ----- | z | ----- | z | 73.57 | d | ||||||||
| 1936 | 50.87 | 50.32 | a | 62.58 | 69.67 | 77.71 | 85.67 | 91.00 | 91.19 | 81.97 | 69.55 | 58.53 | 45.45 | 69.54 | ||||||||||||
| 1937 | 29.16 | 47.52 | a | 56.42 | 64.20 | 78.58 | 83.53 | 92.97 | 92.77 | 85.67 | 71.71 | 59.70 | 51.80 | a | 67.84 | |||||||||||
| 1938 | 50.84 | 46.04 | a | 51.23 | 66.40 | 73.16 | 82.90 | 89.55 | 89.35 | 83.93 | 67.45 | 51.37 | 48.26 | 66.71 | ||||||||||||
| 1939 | 46.29 | 48.96 | 61.03 | 74.80 | 80.74 | 88.77 | 95.35 | 95.74 | 83.07 | 73.52 | 64.83 | 58.97 | 72.67 | |||||||||||||
| 1940 | 54.40 | a | 54.90 | 65.87 | 71.97 | 84.55 | 94.40 | 93.90 | 95.65 | 81.37 | 75.39 | 59.13 | 49.97 | 73.46 | ||||||||||||
| 1941 | 50.81 | 54.25 | 60.06 | 62.86 | a | 79.03 | 84.13 | 93.00 | 87.90 | 81.07 | 68.13 | 62.27 | 49.68 | 69.43 | ||||||||||||
| 1942 | 49.58 | 52.50 | 62.10 | 68.53 | 77.61 | 90.17 | 98.52 | 95.84 | 86.17 | 76.06 | 64.53 | 57.68 | 73.27 | |||||||||||||
| 1943 | 54.19 | 58.75 | 63.80 | a | 72.80 | 81.97 | 84.43 | 94.68 | 93.19 | 89.67 | 75.52 | 62.90 | 48.48 | 73.37 | ||||||||||||
| 1944 | 49.39 | 48.59 | 62.19 | 67.37 | 79.23 | 82.37 | 93.13 | 95.19 | 89.40 | 76.35 | 57.87 | 53.29 | 71.20 | |||||||||||||
| 1945 | 54.48 | 57.89 | a | 57.84 | 71.90 | 78.19 | 88.40 | 98.13 | 91.16 | 88.70 | 72.19 | 60.47 | 50.29 | 72.47 | ||||||||||||
| 1946 | 53.40 | a | 57.44 | a | 63.23 | 75.47 | 80.55 | 90.69 | a | 94.45 | 95.42 | 88.31 | a | 70.40 | a | 53.20 | 54.83 | b | 73.12 | |||||||
| 1947 | 54.70 | a | 62.18 | 67.93 | b | 72.00 | 84.52 | b | 87.79 | a | 94.77 | 90.55 | 90.72 | a | 74.61 | 58.07 | 50.83 | a | 74.06 | |||||||
| 1948 | 58.34 | b | 55.61 | a | 59.26 | d | 71.68 | e | 80.71 | g | 86.60 | 94.23 | 93.03 | 88.23 | 74.71 | 61.00 | 48.55 | 71.93 | a | |||||||
| 1949 | 38.16 | 50.93 | 57.97 | 74.10 | 76.55 | 89.47 | 94.55 | 91.71 | 89.93 | 73.94 | 67.87 | 49.46 | g | 73.20 | a | |||||||||||
| 1950 | 49.55 | 60.61 | 64.74 | 76.17 | 79.45 | 87.37 | 95.77 | 94.68 | 83.97 | 79.45 | 66.83 | 58.94 | 74.79 | |||||||||||||
| 1951 | 53.06 | 56.68 | 63.65 | 70.50 | 79.29 | 87.97 | 96.23 | 93.19 | 90.97 | 75.23 | 60.80 | 50.16 | 73.14 | |||||||||||||
| 1952 | 44.29 | 56.00 | 52.87 | 68.67 | 79.72 | f | 79.53 | 91.74 | 93.61 | c | 86.27 | 81.39 | 57.60 | 48.90 | 69.17 | a | ||||||||||
| 1953 | 58.19 | 57.07 | 63.71 | 69.70 | 69.35 | 84.57 | 96.42 | 92.26 | 88.27 | 73.42 | 62.67 | 54.94 | 72.55 | |||||||||||||
| 1954 | 52.65 | 61.93 | 58.39 | 75.67 | 83.26 | 85.60 | 95.32 | 89.39 | 86.90 | 76.48 | 64.07 | 49.81 | 73.29 | |||||||||||||
| 1955 | 44.03 | 52.21 | 61.87 | 65.77 | 75.00 | 86.00 | 91.23 | 93.52 | 88.17 | 78.26 | 62.23 | 54.48 | 71.06 | |||||||||||||
| 1956 | 54.52 | 53.66 | 66.19 | 66.83 | 76.74 | 89.43 | 92.39 | 90.32 | 89.40 | 71.87 | 60.53 | 56.10 | 72.33 | |||||||||||||
| 1957 | 44.03 | 58.89 | 62.68 | 68.33 | 72.90 | 91.00 | 93.58 | 91.74 | 85.47 | 68.19 | 56.47 | 52.35 | 70.47 | |||||||||||||
| 1958 | 52.87 | 56.54 | 53.23 | 66.10 | 80.87 | 87.27 | 92.65 | 94.48 | 87.10 | 79.06 | 61.90 | 58.06 | 72.51 | |||||||||||||
| 1959 | 54.40 | a | 50.96 | 66.74 | 75.47 | 76.13 | 91.27 | 98.39 | 90.94 | 82.93 | 77.35 | 63.77 | 53.23 | 73.46 | ||||||||||||
| 1960 | 44.97 | 52.59 | 67.42 | 71.50 | 78.48 | 93.20 | 95.81 | 93.94 | 88.70 | 72.55 | 57.37 | 51.13 | 72.30 | |||||||||||||
| 1961 | 53.06 | 57.18 | 61.58 | 71.67 | 75.87 | 91.70 | 96.45 | 89.68 | 82.20 | 72.42 | 57.17 | 48.13 | 71.43 | |||||||||||||
| 1962 | 51.32 | 51.25 | 54.74 | 76.47 | 73.58 | 87.97 | 92.03 | a | 94.87 | 88.53 | 76.10 | 64.53 | 55.10 | 72.21 | ||||||||||||
| 1963 | 51.77 | 61.93 | 59.48 | 64.40 | 79.52 | 82.23 | 94.06 | 90.61 | 85.53 | 75.16 | 61.10 | 55.03 | 71.74 | |||||||||||||
| 1964 | 51.06 | 57.03 | 59.68 | 68.27 | 76.26 | 86.80 | 95.39 | 92.65 | 85.17 | 81.48 | 56.23 | 56.39 | 72.20 | |||||||||||||
| 1965 | 53.97 | 59.61 | 60.45 | 63.57 | 74.90 | 82.93 | ----- | z | 92.26 | 80.90 | 80.58 | 60.57 | 48.77 | 68.96 | a | |||||||||||
| 1966 | 47.71 | 52.54 | 65.74 | 75.43 | 83.13 | 88.97 | 94.10 | 96.23 | 86.27 | 75.58 | 62.10 | 53.13 | 73.41 | |||||||||||||
| 1967 | 53.87 | 59.43 | 63.52 | 57.83 | 78.52 | 84.00 | 96.10 | 96.84 | 83.90 | 79.19 | 64.63 | 47.00 | 72.07 | |||||||||||||
| 1968 | 51.13 | 61.10 | 63.16 | 68.93 | 80.16 | 91.30 | 93.52 | 88.48 | 88.63 | 76.16 | 62.13 | 48.55 | 72.77 | |||||||||||||
| 1969 | 53.42 | 47.71 | 57.06 | 69.97 | 82.00 | 84.63 | 94.81 | 97.55 | 89.33 | 71.32 | 61.93 | 55.13 | 72.07 | |||||||||||||
| 1970 | 52.87 | 58.43 | 61.74 | 64.70 | 81.03 | 89.53 | 96.71 | 96.06 | 85.70 | 73.29 | 62.33 | 46.19 | 72.38 | |||||||||||||
| 1971 | 51.52 | 59.32 | 64.16 | 67.77 | 72.13 | 87.63 | 96.06 | 95.81 | 86.40 | 70.23 | 59.60 | 46.35 | 71.41 | |||||||||||||
| 1972 | 50.40 | a | 61.28 | 72.68 | 70.93 | 80.32 | 88.23 | 98.74 | 92.68 | 83.03 | 68.29 | 56.00 | 49.16 | 72.65 | ||||||||||||
| 1973 | 44.55 | 52.36 | 55.26 | 67.63 | 82.74 | 91.23 | 97.03 | 93.45 | 86.23 | 76.00 | 61.00 | 55.77 | 71.94 | |||||||||||||
| 1974 | 42.65 | 57.86 | 62.58 | 67.10 | 81.58 | 92.27 | 94.61 | 92.10 | 91.07 | 73.10 | 60.87 | 50.10 | 72.16 | |||||||||||||
| 1975 | 53.48 | 54.96 | 58.16 | 59.93 | 77.94 | 89.13 | 94.52 | 92.16 | 87.77 | 73.48 | 61.23 | 57.84 | 71.72 | |||||||||||||
| 1976 | 55.19 | 55.17 | 61.81 | 65.37 | 80.77 | 86.67 | 94.29 | 87.06 | 81.73 | 74.61 | 66.10 | 54.48 | 71.94 | |||||||||||||
| 1977 | 47.35 | 62.46 | 58.06 | 73.17 | 67.42 | 90.47 | 95.77 | 93.16 | 84.67 | 78.45 | 66.30 | 56.77 | 72.84 | |||||||||||||
| 1978 | 50.45 | 55.75 | 63.06 | 64.97 | 77.68 | 89.40 | 95.35 | 93.71 | 82.30 | 80.74 | 57.93 | 49.29 | 71.72 | |||||||||||||
| 1979 | 46.39 | 51.68 | 61.52 | 70.67 | 81.27 | a | 90.47 | 95.39 | 90.74 | 90.33 | 76.58 | 61.47 | 55.60 | a | 72.67 | |||||||||||
| 1980 | 55.74 | 58.52 | 59.16 | 70.23 | 72.90 | 87.07 | 95.87 | 94.29 | 86.60 | 77.94 | 65.33 | 58.42 | 73.51 | |||||||||||||
| 1981 | 55.48 | 59.18 | 59.32 | 73.47 | 79.39 | 94.90 | a | 97.71 | 96.97 | 88.17 | 70.00 | 63.60 | 57.00 | 74.60 | ||||||||||||
| 1982 | 49.13 | 58.39 | 58.06 | 68.23 | 79.90 | 85.27 | 92.26 | 93.43 | a | 82.30 | 71.77 | 56.83 | 50.58 | 70.51 | ||||||||||||
| 1983 | 52.87 | 55.21 | 58.65 | 62.23 | 79.26 | 87.87 | 91.68 | 88.74 | 88.70 | 73.61 | 61.03 | 54.65 | 71.21 | |||||||||||||
| 1984 | 56.06 | 59.31 | 67.61 | 68.60 | 87.32 | 88.47 | 93.94 | 91.10 | 88.37 | ----- | z | 58.57 | 42.77 | a | 72.92 | a | ||||||||||
| 1985 | 51.13 | 56.56 | a | 60.52 | 76.47 | 81.52 | 93.93 | 97.90 | 94.77 | 80.73 | 74.00 | 58.87 | 51.35 | 73.15 | ||||||||||||
| 1986 | 57.58 | 58.18 | 66.65 | 69.77 | 82.29 | 93.33 | 92.42 | 96.58 | 80.90 | 72.29 | 63.63 | 53.00 | 73.88 | |||||||||||||
| 1987 | 49.90 | 56.86 | 60.61 | 77.23 | 79.06 | 91.47 | 91.48 | 94.32 | 88.17 | 78.16 | 59.60 | 45.94 | 72.73 | |||||||||||||
| 1988 | 51.19 | 60.72 | 66.48 | 69.93 | 79.19 | 87.53 | 99.26 | 93.55 | 86.80 | 82.61 | 64.43 | 51.39 | 74.43 | |||||||||||||
| 1989 | 49.55 | 52.82 | 68.84 | 80.03 | 81.26 | 90.27 | 98.81 | 92.23 | 86.33 | 74.16 | 66.17 | 57.39 | 74.82 | |||||||||||||
| 1990 | 54.71 | 55.54 | 67.77 | ----- | z | 79.29 | 91.10 | 97.34 | b | 93.03 | 86.73 | 79.03 | 63.47 | 48.87 | 74.26 | a | ||||||||||
| 1991 | 53.19 | 65.39 | 54.77 | 69.10 | 74.39 | 86.70 | 95.45 | 92.29 | 88.97 | 80.87 | 63.63 | 52.03 | 73.07 | |||||||||||||
| 1992 | 50.74 | 57.00 | 59.71 | 75.13 | 82.68 | 87.10 | 92.10 | 95.58 | 89.10 | 78.87 | 60.33 | 48.29 | 73.05 | |||||||||||||
| 1993 | 48.29 | 52.56 | a | 66.42 | 74.27 | 81.06 | 88.53 | 94.03 | 95.10 | 87.57 | i | 77.94 | 62.70 | 56.00 | 72.44 | a | ||||||||||
| 1994 | 59.10 | 54.00 | 69.70 | a | 73.67 | 80.00 | 95.53 | 99.81 | 98.94 | 88.67 | 74.10 | 55.70 | 54.42 | 75.30 | ||||||||||||
| 1995 | 48.55 | 66.21 | 62.00 | 70.03 | 75.39 | c | 87.33 | 96.20 | a | 97.81 | 92.43 | 81.42 | 72.53 | 57.67 | a | 75.63 | ||||||||||
| 1996 | 60.23 | 60.97 | 66.58 | 77.07 | 85.55 | 93.80 | 100.45 | 99.55 | 89.10 | 76.35 | 64.37 | 57.00 | 77.58 | |||||||||||||
| 1997 | 56.10 | ----- | z | 74.06 | 73.60 | 88.90 | 90.73 | 94.68 | 96.19 | 90.76 | a | 78.16 | 64.57 | ----- | z | 80.78 | b | |||||||||
| 1998 | 56.16 | 51.43 | 64.26 | 66.10 | 71.06 | 85.70 | 98.55 | 100.19 | 86.62 | a | 75.10 | 64.50 | ----- | z | 74.52 | a | ||||||||||
| 1999 | 58.32 | 60.11 | 66.00 | 66.30 | 81.29 | 90.59 | a | 94.84 | 93.23 | 90.70 | 84.42 | 69.33 | 60.26 | 76.28 | ||||||||||||
| 2000 | 59.23 | 59.10 | 65.42 | 77.07 | 87.32 | 94.67 | 96.71 | 96.61 | 89.87 | 76.45 | 60.27 | 57.87 | 76.72 | |||||||||||||
| 2001 | 49.48 | 49.00 | 64.87 | 68.83 | 88.55 | 92.37 | 92.65 | 96.94 | 91.23 | 82.77 | 64.23 | 52.06 | 74.42 | |||||||||||||
| 2002 | 54.13 | 63.46 | 64.35 | 75.80 | 81.65 | 98.13 | 103.23 | 96.94 | 90.90 | 76.94 | 64.80 | 51.81 | 76.84 | |||||||||||||
| 2003 | 60.68 | 56.00 | 66.39 | 66.33 | 80.97 | 94.20 | 103.61 | 94.97 | ----- | z | 85.77 | 58.70 | 53.42 | 74.64 | a | |||||||||||
| 2004 | 55.35 | 54.10 | 74.35 | 74.73 | 83.71 | 93.00 | 96.71 | 94.52 | 89.17 | 73.52 | 59.80 | 52.55 | 75.13 | |||||||||||||
| 2005 | 51.68 | 55.54 | 65.26 | 69.97 | 81.94 | 87.20 | ----- | z | 95.77 | 86.07 | a | 76.68 | 67.87 | 57.65 | 72.33 | a | ||||||||||
| 2006 | 56.94 | 63.46 | 59.58 | 68.69 | a | 86.45 | 96.00 | 101.63 | a | 102.58 | 93.90 | 76.77 | 70.93 | p | 53.65 | 78.15 | a | |||||||||
| 2007 | 46.20 | a | 56.38 | b | ----- | z | 63.56 | u | 87.73 | i | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 73.93 | c | 55.48 | 58.00 | h | |
| 2008 | 53.20 | a | 61.21 | a | 71.81 | 77.77 | 83.16 | 96.40 | 102.00 | j | 101.19 | e | 96.53 | k | 85.33 | a | 75.33 | i | 57.84 | 76.43 | c | |||||
| 2009 | 63.21 | c | 59.29 | 69.05 | i | 76.73 | 93.61 | 89.50 | 104.60 | a | 99.00 | 99.10 | 79.10 | 72.90 | 56.00 | 81.19 | a | |||||||||
| 2010 | 56.61 | 62.36 | 69.23 | 71.10 | a | 79.65 | 96.23 | 103.03 | 98.57 | c | 95.03 | a | 79.35 | 67.77 | 57.74 | 78.06 | ||||||||||
| 2011 | 59.68 | 60.79 | 66.42 | 75.97 | 79.06 | n | 91.80 | 98.71 | 100.35 | 95.50 | 82.23 | 63.60 | 57.00 | 77.46 | a | |||||||||||
| 2012 | 62.03 | b | 62.86 | 68.19 | 77.50 | 88.77 | 96.47 | 97.03 | 101.90 | 98.10 | a | 85.71 | 72.07 | 59.52 | 80.85 | |||||||||||
| 2013 | 58.52 | 64.39 | 76.52 | 83.31 | a | 91.26 | 103.37 | 106.53 | a | 100.39 | 94.28 | a | 79.89 | c | 63.43 | 54.70 | a | 81.38 | ||||||||
| 2014 | 62.42 | 65.82 | 68.35 | 75.70 | 85.26 | 94.97 | 98.81 | 91.23 | 87.67 | 78.52 | 64.60 | 50.00 | 76.94 | |||||||||||||
| 2015 | 54.45 | 64.50 | 69.26 | 71.73 | 75.06 | 92.72 | a | 89.45 | 94.74 | 87.77 | 72.94 | 57.23 | 49.00 | b | 73.24 | |||||||||||
| 2016 | 48.45 | 60.97 | 65.97 | 70.63 | 75.39 | 94.70 | 96.94 | 93.22 | v | 83.57 | 72.42 | 60.23 | 48.19 | 70.68 | a | |||||||||||
| 2017 | 44.65 | 58.47 | m | 66.41 | d | 69.90 | 78.26 | 92.20 | 94.36 | t | 92.52 | ----- | z | 79.74 | ----- | z | ----- | z | 74.81 | e | ||||||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 52.15 | 57.05 | 63.40 | 70.78 | 79.73 | 89.44 | 95.72 | 94.06 | 87.29 | 75.97 | 62.34 | 52.75 | 73.24 | |||||||||||||
| S.D. | 5.29 | 4.56 | 4.94 | 4.57 | 4.75 | 4.12 | 3.28 | 3.17 | 3.75 | 4.13 | 4.12 | 3.98 | 2.35 | |||||||||||||
| SKEW | -0.94 | -0.22 | 0.06 | -0.06 | 0.04 | 0.30 | 0.79 | 0.39 | 0.52 | 0.22 | 0.32 | -0.01 | 0.78 | |||||||||||||
| MAX | 63.21 | 66.21 | 76.52 | 83.31 | 93.61 | 103.37 | 106.53 | 102.58 | 99.10 | 85.77 | 73.93 | 61.26 | 81.38 | |||||||||||||
| MIN | 29.16 | 46.04 | 51.23 | 57.83 | 67.42 | 79.53 | 88.90 | 87.06 | 80.73 | 67.45 | 51.37 | 42.77 | 66.71 | |||||||||||||
| YRS | 93 | 92 | 92 | 92 | 91 | 94 | 90 | 93 | 89 | 93 | 91 | 90 | 75 | |||||||||||||