| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1917 | ----- | z | ----- | z | 34.84 | 45.13 | 51.34 | 58.85 | 70.74 | 67.32 | l | 62.40 | 50.35 | 45.33 | 42.85 | a | 51.32 | |||||||||
| 1918 | 35.82 | a | 33.46 | 43.45 | 45.93 | 50.95 | 67.03 | 67.47 | 62.73 | 61.43 | 50.77 | 36.26 | g | 30.50 | 49.96 | |||||||||||
| 1919 | 34.15 | 32.66 | 40.81 | 48.48 | 53.40 | 60.38 | 69.63 | 68.68 | 58.37 | 42.33 | a | 36.75 | 22.90 | 47.38 | ||||||||||||
| 1920 | 31.10 | a | 35.89 | a | 38.47 | 42.15 | 49.90 | 57.48 | 68.42 | 66.37 | a | 56.88 | 45.55 | 38.70 | 33.92 | 47.07 | ||||||||||
| 1921 | 32.10 | 32.95 | 41.63 | 43.20 | 52.65 | 61.55 | 65.94 | 67.29 | 53.13 | 51.05 | 40.93 | 31.42 | 47.82 | |||||||||||||
| 1922 | 21.19 | e | 29.21 | 34.55 | 41.92 | 51.13 | 63.15 | 69.16 | 67.76 | 61.55 | 51.58 | 35.82 | 28.23 | 46.27 | ||||||||||||
| 1923 | 34.95 | a | 29.62 | 37.90 | 45.65 | 51.44 | 56.60 | 66.90 | 66.45 | 59.57 | 45.87 | 39.52 | 31.13 | 47.13 | ||||||||||||
| 1924 | 25.74 | 37.90 | 34.98 | 45.27 | 58.68 | 59.58 | 66.08 | 63.55 | a | 59.37 | 49.94 | 38.65 | 21.94 | 46.81 | ||||||||||||
| 1925 | 34.11 | 39.70 | 40.74 | 47.02 | 55.19 | 61.23 | b | 71.15 | h | 63.48 | 55.57 | 46.23 | 37.53 | 32.14 | b | 46.63 | ||||||||||
| 1926 | 27.55 | 40.57 | 43.56 | 52.18 | 53.65 | 64.26 | a | 71.24 | 67.52 | 52.56 | c | 49.05 | 43.20 | 30.90 | b | 49.69 | ||||||||||
| 1927 | 29.15 | d | 36.57 | 38.77 | 43.92 | 48.84 | 60.28 | 67.58 | 66.87 | 53.87 | 50.08 | 42.22 | 24.76 | 46.91 | ||||||||||||
| 1928 | 29.71 | 31.14 | 41.32 | 43.70 | 57.63 | 58.20 | 68.89 | 65.68 | 59.22 | 48.98 | 39.43 | 28.68 | c | 47.71 | ||||||||||||
| 1929 | 21.59 | c | 24.46 | a | 39.03 | b | 43.00 | 53.32 | 58.48 | 66.98 | 68.89 | 53.85 | 50.21 | 36.62 | 39.58 | 46.34 | ||||||||||
| 1930 | 16.24 | 39.09 | 40.81 | 51.15 | 51.52 | 57.95 | 67.23 | 68.29 | 58.82 | h | 46.03 | 37.57 | 25.77 | 45.60 | ||||||||||||
| 1931 | 31.94 | 34.79 | 40.89 | 47.37 | 57.08 | 60.10 | 69.48 | 66.92 | a | 57.03 | 48.42 | a | 33.55 | 29.11 | 48.06 | |||||||||||
| 1932 | 27.66 | 26.71 | 37.95 | 46.93 | a | 52.48 | 61.88 | 64.56 | 64.06 | 57.48 | 48.26 | 42.72 | 23.97 | 46.22 | ||||||||||||
| 1933 | 29.56 | 23.39 | 38.44 | 44.50 | a | 48.23 | 61.53 | 67.45 | a | 64.90 | 54.17 | 52.85 | a | 40.70 | 40.48 | 47.18 | ||||||||||
| 1934 | 38.37 | 41.30 | 46.30 | a | 50.97 | 56.50 | 58.12 | 66.65 | 67.15 | 56.60 | 51.90 | 44.98 | 32.67 | a | 50.96 | |||||||||||
| 1935 | 33.53 | a | 35.52 | 36.32 | 44.43 | 51.73 | 59.43 | 65.60 | a | 64.37 | 60.88 | 47.18 | c | 34.13 | 32.42 | 47.13 | ||||||||||
| 1936 | 30.45 | 23.16 | 38.30 | a | 50.07 | 58.65 | 61.48 | 68.77 | a | 65.98 | 55.79 | a | 50.53 | 35.33 | a | 34.63 | 47.76 | |||||||||
| 1937 | 13.05 | 30.11 | 40.66 | 44.03 | 53.89 | 59.13 | 67.66 | 63.15 | 59.65 | 51.60 | a | 43.13 | 36.98 | a | 46.92 | |||||||||||
| 1938 | 35.11 | 35.80 | 39.00 | 47.48 | 52.58 | 61.05 | 67.87 | 63.52 | 62.77 | 50.11 | 33.55 | 34.10 | 48.58 | |||||||||||||
| 1939 | 34.37 | 28.88 | 40.79 | 48.67 | 55.11 | 56.43 | 67.45 | 66.74 | 59.43 | 48.29 | 41.80 | 38.08 | 48.84 | |||||||||||||
| 1940 | 32.82 | 37.93 | 42.55 | 46.38 | 56.29 | 62.92 | 66.89 | 66.71 | 59.78 | a | 50.68 | 33.58 | 35.61 | 49.34 | ||||||||||||
| 1941 | 34.59 | b | 37.75 | 43.26 | 47.03 | 53.16 | 58.40 | 67.69 | 64.21 | 52.57 | 46.48 | 41.22 | 34.84 | 48.43 | ||||||||||||
| 1942 | 25.89 | 31.38 | 37.58 | 48.12 | 49.60 | 55.82 | 67.02 | 65.11 | 57.32 | 50.05 | 39.43 | 33.45 | 46.73 | |||||||||||||
| 1943 | 24.87 | 35.12 | 37.45 | 49.10 | 48.55 | 53.54 | b | 65.24 | 62.60 | 59.83 | 49.35 | 40.45 | 32.31 | 46.53 | ||||||||||||
| 1944 | 29.38 | a | 32.19 | 36.37 | a | 45.88 | 53.15 | 56.88 | a | 65.18 | 63.31 | 58.82 | 52.23 | 36.19 | a | 29.32 | 46.57 | |||||||||
| 1945 | 31.40 | 36.41 | 38.39 | 44.17 | 53.05 | 57.68 | 67.71 | 65.95 | 55.55 | 51.16 | 38.22 | 30.95 | 47.55 | |||||||||||||
| 1946 | 31.58 | 32.68 | 40.40 | 47.63 | 53.53 | 57.83 | 65.26 | 64.35 | 55.08 | 42.89 | 35.82 | 35.58 | 46.89 | |||||||||||||
| 1947 | 24.79 | 38.84 | 43.23 | 46.23 | 57.45 | 56.32 | 65.65 | 63.26 | 58.40 | 51.37 | 37.02 | 34.03 | 48.05 | |||||||||||||
| 1948 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 62.10 | 62.31 | 56.10 | 48.89 | 37.00 | 24.81 | 48.53 | |||||||
| 1949 | 9.65 | 31.46 | 40.98 | 49.32 | 56.11 | 58.33 | 65.23 | 68.18 | 61.45 | h | 42.06 | 42.37 | 29.98 | 44.88 | ||||||||||||
| 1950 | 21.27 | a | 35.27 | 38.13 | 43.47 | a | 50.69 | 58.83 | 66.35 | 67.34 | 57.14 | a | 51.35 | h | 41.12 | a | 39.35 | a | 47.18 | |||||||
| 1951 | 28.27 | a | 35.67 | a | 35.68 | a | 46.86 | a | 53.40 | b | 57.70 | c | 67.57 | d | 58.17 | s | 58.92 | d | 46.33 | b | 37.95 | b | 26.56 | e | 44.99 | |
| 1952 | 26.50 | b | 29.97 | 34.68 | 49.46 | b | 52.68 | a | 58.62 | 66.04 | c | 65.38 | f | 61.62 | d | 51.58 | e | 33.24 | g | 33.75 | a | 46.49 | ||||
| 1953 | 41.39 | d | 34.71 | b | 40.44 | 45.20 | 49.55 | 55.48 | e | 66.47 | b | 63.52 | f | 60.46 | b | 50.95 | i | 44.00 | 33.23 | a | 47.09 | |||||
| 1954 | 32.42 | 38.04 | 38.27 | 45.72 | 53.53 | 55.89 | c | 66.79 | 61.53 | 56.17 | a | 45.85 | 41.70 | 29.98 | 47.16 | |||||||||||
| 1955 | 27.71 | 27.85 | a | 30.43 | a | 40.31 | c | 48.30 | f | 60.23 | b | 64.17 | a | 65.50 | 57.25 | b | 49.20 | h | 33.98 | 31.55 | b | 43.90 | ||||
| 1956 | 31.52 | 25.91 | 36.97 | 46.94 | c | 54.19 | 55.74 | a | 66.53 | 64.31 | 58.58 | 45.67 | a | 35.50 | 32.13 | e | 46.17 | |||||||||
| 1957 | 17.19 | 33.41 | 42.14 | i | 47.65 | c | 55.05 | 61.06 | d | 65.60 | g | 62.82 | 60.29 | a | 45.88 | a | 32.12 | f | 33.46 | c | 46.31 | |||||
| 1958 | 34.94 | 41.07 | 36.92 | 44.12 | 58.35 | 62.05 | a | 68.69 | 69.76 | j | 57.20 | 51.47 | 39.33 | 37.00 | 48.29 | |||||||||||
| 1959 | 29.36 | j | 32.71 | i | 40.63 | h | 48.07 | b | 51.11 | 62.57 | 67.84 | c | 62.50 | i | 55.25 | 47.81 | b | 36.58 | 32.90 | 50.27 | ||||||
| 1960 | 27.30 | a | 31.39 | b | 41.05 | 46.82 | 48.48 | 58.48 | d | 71.77 | 62.30 | a | 59.00 | 49.29 | 38.42 | 33.21 | 47.29 | |||||||||
| 1961 | 34.45 | a | 39.98 | 40.47 | a | 45.13 | 51.22 | d | 65.13 | 70.02 | a | 72.52 | a | 52.95 | b | 47.71 | 36.15 | 31.56 | 48.94 | |||||||
| 1962 | 25.65 | 31.54 | 38.03 | 48.70 | 49.47 | 58.92 | 65.26 | 66.00 | e | 59.82 | 47.82 | 39.88 | b | 35.95 | 47.25 | |||||||||||
| 1963 | 24.81 | 44.07 | 40.39 | d | 43.43 | a | 54.10 | 58.37 | 63.37 | 66.71 | b | 64.95 | 51.19 | b | 41.14 | a | 31.02 | 48.63 | ||||||||
| 1964 | 30.82 | 31.57 | 37.19 | 43.73 | 51.13 | a | 57.70 | 66.48 | b | 62.58 | 56.00 | 51.03 | 38.07 | 29.81 | b | 46.34 | ||||||||||
| 1965 | 33.05 | a | 36.45 | 36.11 | 47.13 | 51.68 | a | 59.12 | 66.55 | 64.77 | 52.96 | g | 53.56 | 41.88 | 33.12 | e | 47.58 | |||||||||
| 1966 | 32.40 | g | 32.80 | a | 40.44 | 45.78 | 55.12 | j | 58.20 | 64.95 | a | 65.97 | a | 62.33 | 48.15 | 40.36 | a | 34.23 | 49.32 | |||||||
| 1967 | 35.76 | 37.80 | 38.68 | 40.27 | b | 51.69 | 60.14 | b | 68.42 | 70.66 | 65.27 | 49.44 | 38.02 | 28.79 | 48.74 | |||||||||||
| 1968 | 31.18 | c | 38.81 | 43.00 | 43.25 | 51.16 | b | 58.78 | a | 68.27 | 62.28 | a | 58.02 | b | 47.89 | 37.48 | b | 31.03 | a | 47.60 | ||||||
| 1969 | 27.71 | 32.54 | 38.94 | 45.69 | a | 55.38 | a | 61.55 | 64.35 | 64.82 | 58.32 | 44.52 | 40.18 | 35.48 | a | 47.46 | ||||||||||
| 1970 | 34.03 | 39.95 | 38.06 | 40.13 | 52.10 | 62.58 | 67.82 | 67.55 | 52.70 | 45.10 | 39.65 | 29.27 | 47.41 | |||||||||||||
| 1971 | 33.17 | b | 35.14 | 36.00 | 44.78 | 53.90 | 56.70 | 66.39 | 71.06 | 52.25 | 44.95 | 38.38 | 28.31 | 46.75 | ||||||||||||
| 1972 | 27.16 | 34.07 | 43.23 | a | 43.38 | 54.94 | 59.50 | 65.72 | a | 67.50 | 52.90 | 47.08 | 38.05 | 23.41 | b | 46.41 | ||||||||||
| 1973 | 28.60 | 37.00 | 40.69 | 43.28 | 53.55 | a | 59.93 | 67.92 | 67.06 | 58.02 | 42.89 | v | ----- | z | ----- | z | 50.67 | |||||||||
| 1974 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1975 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1976 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1977 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1978 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1979 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1980 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1981 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1982 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1983 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1984 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1985 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1986 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1987 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1988 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 64.45 | 57.15 | 55.11 | 37.80 | 28.21 | 48.54 | ||||||
| 1989 | 27.53 | 21.93 | 38.48 | b | 47.60 | 50.92 | 59.92 | 66.39 | 61.58 | a | 57.10 | 46.90 | 39.83 | 34.35 | 46.05 | |||||||||||
| 1990 | 34.03 | 31.82 | 40.74 | 48.82 | 49.90 | 58.15 | 67.55 | 66.15 | 63.55 | 47.27 | 39.88 | 21.23 | a | 47.42 | ||||||||||||
| 1991 | 26.87 | 40.36 | 38.40 | 43.68 | 48.15 | 54.13 | 66.27 | 68.84 | 60.55 | 47.81 | 37.40 | 34.74 | 47.27 | |||||||||||||
| 1992 | 34.68 | 41.33 | 44.55 | ----- | z | 56.63 | 63.41 | c | ----- | z | 66.16 | 57.20 | 50.85 | 34.72 | 27.72 | a | 47.72 | |||||||||
| 1993 | 23.82 | 27.74 | a | 39.55 | 44.57 | 56.68 | 56.28 | 57.42 | 61.79 | 57.88 | 49.68 | 31.47 | 33.82 | 45.06 | ||||||||||||
| 1994 | 36.29 | 32.91 | 42.29 | 48.22 | 55.08 | 54.66 | a | 68.69 | 67.55 | 61.73 | 47.39 | 32.90 | a | 31.47 | 48.26 | |||||||||||
| 1995 | 35.13 | 39.18 | 40.37 | a | 44.02 | 52.53 | a | 57.30 | 66.11 | 62.84 | ----- | z | 45.32 | 42.48 | 33.53 | 47.16 | ||||||||||
| 1996 | 32.03 | a | 33.66 | 40.94 | 47.03 | 49.23 | 59.48 | 67.85 | 66.48 | 56.42 | 49.10 | 39.95 | 34.74 | 48.08 | ||||||||||||
| 1997 | 32.40 | 34.39 | 41.85 | 45.62 | 57.03 | 58.91 | a | 65.55 | 68.63 | 65.15 | m | ----- | z | 41.37 | 31.65 | 47.74 | ||||||||||
| 1998 | 35.19 | 36.96 | 40.85 | 45.95 | 51.10 | 58.63 | ----- | z | 69.85 | a | ----- | z | 47.56 | ----- | z | 28.10 | a | 46.02 | ||||||||
| 1999 | 35.63 | a | 35.59 | a | ----- | z | 44.91 | a | 51.68 | a | 59.10 | 67.66 | 72.11 | ----- | z | 54.45 | 47.52 | 32.05 | 50.07 | |||||||
| 2000 | 32.89 | 38.53 | 40.15 | 52.20 | b | ----- | z | ----- | z | ----- | z | ----- | z | 58.91 | g | ----- | z | 32.48 | 31.52 | 37.96 | ||||||
| 2001 | 28.98 | 33.05 | 41.71 | 44.27 | 55.03 | 57.18 | 66.58 | g | 68.97 | m | ----- | z | 48.98 | d | ----- | z | ----- | z | 44.17 | |||||||
| 2002 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 2003 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 2004 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 2005 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 68.42 | ----- | z | ----- | z | ----- | z | ----- | z | 68.42 | ||
| 2006 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 2007 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 2008 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 42.08 | e | 29.29 | 35.69 | ||
| 2009 | ----- | z | 34.38 | k | 35.85 | k | 44.38 | q | 47.29 | q | ----- | z | ----- | z | ----- | z | 70.50 | z | 40.50 | z | ----- | z | 11.00 | z | 9999.00 | |
| 2010 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 33.78 | h | 9999.00 | |
| 2011 | 28.74 | d | 31.20 | c | 38.81 | b | 40.98 | d | 48.59 | c | 56.26 | c | 64.40 | g | 69.71 | j | 63.25 | f | 50.05 | k | 36.31 | n | 29.97 | l | 40.76 | |
| 2012 | 32.96 | e | 34.63 | f | 39.43 | d | 47.21 | a | 50.04 | h | 57.65 | m | 70.70 | c | 69.19 | d | 62.05 | j | 47.03 | p | 43.06 | u | 26.33 | v | 51.90 | |
| 2013 | 20.88 | w | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 29.77 | 34.12 | 39.44 | 45.88 | 52.94 | 59.11 | 66.95 | 65.90 | 57.94 | 48.69 | 38.81 | 31.65 | 47.46 | |||||||||||||
| S.D. | 5.77 | 4.77 | 2.73 | 2.69 | 2.77 | 2.58 | 2.18 | 2.61 | 3.12 | 2.77 | 3.32 | 4.28 | 1.08 | |||||||||||||
| SKEW | -1.18 | -0.46 | -0.35 | 0.13 | 0.23 | 0.49 | -1.10 | 0.32 | 0.11 | -0.16 | 0.04 | -0.17 | 0.80 | |||||||||||||
| MAX | 41.39 | 44.07 | 46.30 | 52.20 | 58.68 | 67.03 | 71.77 | 72.52 | 65.27 | 55.11 | 47.52 | 42.85 | 50.96 | |||||||||||||
| MIN | 9.65 | 21.93 | 30.43 | 40.13 | 48.15 | 53.54 | 57.42 | 61.53 | 52.25 | 42.06 | 31.47 | 21.23 | 45.06 | |||||||||||||
| NO YRS | 68 | 68 | 68 | 70 | 67 | 69 | 65 | 65 | 62 | 65 | 66 | 70 | 46 | |||||||||||||