| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1934 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1935 | 14.00 | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1936 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1937 | -23.80 | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1938 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1939 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1940 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1941 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1942 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1943 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1944 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1945 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 34.26 | 28.24 | a | 24.39 | 28.96 | |||
| 1946 | 24.68 | 25.79 | 28.06 | 29.57 | 37.42 | 42.67 | 47.03 | a | 43.61 | 37.27 | 30.30 | a | 25.53 | 27.10 | 33.25 | |||||||||||
| 1947 | 19.03 | 26.43 | 29.03 | 31.47 | 38.16 | 38.50 | 41.77 | 39.43 | c | 38.70 | 35.68 | 28.80 | 27.10 | a | 32.84 | |||||||||||
| 1948 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 42.67 | a | 41.63 | a | 35.87 | 31.28 | b | 25.93 | a | 13.77 | 31.86 | |||
| 1949 | 4.18 | c | 19.48 | a | 27.42 | 29.03 | 36.87 | 36.03 | 39.19 | 39.53 | a | 35.83 | 25.58 | 28.86 | b | 20.13 | 28.51 | |||||||||
| 1950 | 7.50 | a | 24.57 | 24.69 | b | 27.43 | b | 31.03 | 40.82 | b | 43.93 | a | 44.58 | 39.90 | a | 38.45 | 33.00 | a | 32.23 | a | 32.34 | |||||
| 1951 | 21.29 | 25.85 | a | 24.19 | 27.82 | b | 35.40 | a | 39.64 | b | 43.83 | a | 40.00 | d | 39.58 | d | 32.52 | 28.60 | e | 20.10 | a | 31.57 | ||||
| 1952 | 20.79 | b | 26.86 | h | 23.43 | c | 30.83 | a | 34.35 | 42.70 | 45.79 | c | 46.47 | a | 42.52 | a | 35.77 | a | 21.38 | a | 23.31 | b | 33.39 | |||
| 1953 | 33.03 | 25.96 | 27.14 | c | 29.00 | a | 33.79 | b | 37.38 | a | 40.53 | a | 44.07 | c | 39.86 | b | 33.07 | a | 32.53 | 27.59 | b | 33.66 | ||||
| 1954 | 20.83 | a | 28.18 | 19.81 | 28.23 | 33.06 | 38.93 | 44.03 | 43.32 | 39.27 | 30.81 | 32.20 | 23.45 | 31.84 | ||||||||||||
| 1955 | 22.13 | 20.21 | 22.31 | b | 26.10 | a | 32.57 | a | 40.10 | 42.10 | 39.50 | a | 38.07 | c | 33.65 | 23.97 | 22.52 | 30.27 | ||||||||
| 1956 | 24.65 | 21.43 | a | 26.93 | b | 29.19 | c | 39.70 | a | 38.67 | 46.03 | 43.61 | 39.23 | 32.61 | 24.87 | 27.03 | 32.83 | |||||||||
| 1957 | 7.42 | 24.86 | 29.80 | a | 31.20 | 39.97 | 41.33 | 41.97 | 39.26 | 41.47 | 35.32 | 24.17 | 27.43 | a | 32.02 | |||||||||||
| 1958 | 27.61 | 32.75 | 24.97 | 29.07 | 39.42 | 45.57 | 47.81 | 48.58 | 40.23 | 34.77 | 29.37 | 30.97 | 35.93 | |||||||||||||
| 1959 | 25.57 | a | 22.64 | 26.77 | 27.43 | 31.13 | 40.13 | 44.77 | 41.45 | 39.70 | 33.29 | 23.30 | 22.84 | 31.59 | ||||||||||||
| 1960 | 18.39 | 21.86 | 27.63 | a | 30.80 | 33.55 | 38.40 | 46.26 | 40.81 | 37.67 | 34.35 | 24.13 | 24.58 | 31.54 | ||||||||||||
| 1961 | 26.84 | 29.18 | 25.65 | 29.83 | 31.48 | 43.37 | 44.03 | 45.61 | 32.37 | 29.48 | 22.57 | 23.19 | 31.97 | |||||||||||||
| 1962 | 19.17 | a | 24.86 | 23.58 | 27.71 | b | 31.23 | 36.13 | 39.10 | b | 41.80 | a | 38.40 | 33.59 | b | 30.44 | c | 26.36 | f | 31.46 | ||||||
| 1963 | 13.78 | d | 31.39 | e | 26.11 | d | 28.52 | c | 33.68 | c | 36.85 | c | 38.31 | e | 39.23 | a | 42.43 | b | 32.77 | 29.00 | 22.68 | 31.23 | ||||
| 1964 | 22.87 | a | 19.36 | a | 16.19 | d | 21.59 | a | 26.61 | c | ----- | z | 42.28 | b | 38.30 | d | 32.79 | a | 30.17 | a | 25.62 | a | 20.24 | f | 27.58 | |
| 1965 | 26.07 | c | 23.84 | i | ----- | z | 29.68 | b | 29.52 | 36.93 | 42.69 | b | 43.38 | b | 31.79 | b | 35.17 | b | 31.79 | a | 23.03 | 33.01 | ||||
| 1966 | 27.03 | a | 23.89 | 24.80 | a | 23.93 | c | 31.10 | 38.20 | 40.97 | b | 40.03 | b | 40.56 | c | 31.20 | a | 32.12 | d | 26.67 | a | 31.71 | ||||
| 1967 | 26.97 | b | 26.11 | a | 23.73 | a | 25.33 | c | 32.90 | 39.83 | 43.54 | c | 46.67 | a | 42.73 | 34.84 | 27.97 | 21.77 | 32.70 | |||||||
| 1968 | 23.00 | 28.83 | 28.16 | 25.97 | 34.52 | b | 39.46 | b | 43.61 | 44.37 | a | 38.79 | b | 32.17 | a | 29.17 | a | 18.63 | d | 32.22 | ||||||
| 1969 | 13.52 | 20.04 | 23.32 | 28.59 | a | 37.70 | a | 44.63 | 42.61 | c | 40.30 | a | 39.25 | b | 30.35 | 27.83 | 24.30 | a | 31.04 | |||||||
| 1970 | 24.32 | 26.12 | b | 25.04 | d | 23.63 | 32.52 | 43.21 | b | 43.13 | 40.45 | b | 33.13 | 29.67 | a | 27.69 | a | 22.32 | 30.94 | |||||||
| 1971 | 24.90 | 23.96 | a | 25.10 | a | 26.03 | a | 34.10 | a | 37.60 | 45.13 | 46.84 | 34.86 | a | 28.90 | a | 27.00 | a | 21.53 | a | 31.33 | |||||
| 1972 | 21.03 | 25.90 | 29.90 | 25.69 | a | 35.74 | 41.33 | 44.66 | b | 43.80 | a | 34.23 | 29.48 | 29.50 | b | 14.25 | c | 31.29 | ||||||||
| 1973 | 20.07 | a | 26.56 | a | 25.77 | a | 27.83 | 35.42 | 39.72 | e | 42.52 | b | 41.67 | a | 40.31 | d | 31.54 | c | 27.59 | a | 28.45 | 32.29 | ||||
| 1974 | 17.32 | 25.73 | b | 26.54 | c | 28.39 | b | 31.97 | a | 41.40 | e | 41.55 | b | 42.52 | 35.80 | 30.10 | 28.93 | b | 24.00 | 31.19 | ||||||
| 1975 | 24.23 | a | 22.50 | 22.64 | c | 24.97 | 30.46 | c | 37.32 | e | 47.52 | b | 40.45 | b | 36.59 | a | 35.97 | b | 27.00 | b | 26.83 | b | 31.37 | |||
| 1976 | 25.63 | a | 22.79 | 24.03 | 27.48 | a | 30.54 | c | 32.70 | c | 40.14 | c | 43.83 | b | 37.69 | a | 26.60 | f | 29.08 | d | 19.43 | a | 30.30 | |||
| 1977 | 15.04 | d | 22.82 | 22.17 | g | 24.64 | b | 31.81 | d | 39.93 | b | 41.82 | c | 48.36 | c | 36.35 | d | 31.83 | b | 25.36 | b | 27.18 | c | 31.38 | ||
| 1978 | ----- | z | ----- | z | ----- | z | 29.96 | d | 31.70 | a | 39.32 | b | 43.41 | d | 43.59 | d | 38.56 | e | 28.63 | d | ----- | z | ----- | z | 36.45 | |
| 1979 | 2.86 | c | 25.75 | d | 27.40 | a | 29.46 | d | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 36.33 | a | 24.96 | c | 27.43 | a | 24.89 | |
| 1980 | 18.77 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 33.62 | g | 30.30 | 29.94 | 26.34 | ||||
| 1981 | 24.72 | b | 24.74 | a | 27.10 | a | 27.22 | g | 32.53 | l | 38.03 | a | 37.15 | d | ----- | z | 34.70 | g | ----- | z | ----- | z | ----- | z | 30.35 | |
| 1982 | 17.38 | j | 23.36 | 25.48 | 25.65 | j | 30.74 | 42.43 | 43.42 | 40.68 | 34.81 | i | 29.25 | k | 22.67 | 20.94 | 31.21 | |||||||||
| 1983 | 27.13 | a | 29.46 | 32.00 | l | 26.93 | 35.48 | d | 36.23 | 41.39 | 44.33 | a | 34.46 | q | 34.39 | 29.93 | 15.61 | 32.09 | ||||||||
| 1984 | 25.81 | 25.93 | 29.19 | 27.20 | 32.73 | a | 36.70 | 41.13 | 41.57 | c | 34.13 | 29.73 | a | 27.84 | e | 18.55 | b | 30.88 | ||||||||
| 1985 | 20.23 | i | 20.39 | 22.39 | ----- | z | 27.37 | a | 37.97 | 42.77 | 42.71 | 36.18 | h | 27.26 | 10.80 | 13.38 | b | 27.23 | ||||||||
| 1986 | 29.78 | m | 27.39 | 31.08 | g | 26.63 | 34.77 | 42.31 | d | 39.80 | a | 42.00 | a | 36.36 | e | 31.81 | 29.07 | 24.65 | 33.48 | |||||||
| 1987 | ----- | z | 26.79 | 28.84 | 30.90 | 36.76 | f | 40.25 | b | 43.07 | a | 39.55 | 35.80 | 27.39 | 26.23 | 21.57 | a | 32.04 | ||||||||
| 1988 | 22.79 | c | 23.52 | 25.84 | 31.90 | 30.65 | 39.52 | a | 41.71 | 37.90 | 34.04 | d | 35.06 | 29.80 | 22.67 | a | 31.28 | |||||||||
| 1989 | 22.29 | 12.93 | 27.29 | 33.03 | 32.81 | 40.17 | a | 38.16 | 39.06 | 34.00 | b | 29.00 | 27.32 | b | 21.84 | 29.83 | ||||||||||
| 1990 | 25.35 | 21.61 | 26.23 | ----- | z | 30.00 | 37.53 | 43.84 | 45.35 | 39.43 | 30.06 | 27.23 | 11.32 | 30.72 | ||||||||||||
| 1991 | 19.52 | ----- | z | ----- | z | ----- | z | 31.48 | 33.77 | 41.16 | 40.84 | 33.70 | 28.68 | 30.73 | ----- | z | 32.48 | |||||||||
| 1992 | 24.35 | 29.07 | 31.23 | a | 31.89 | b | ----- | z | 41.33 | ----- | z | 39.71 | ----- | z | 34.03 | 26.00 | 15.53 | a | 30.35 | |||||||
| 1993 | 11.71 | 15.39 | 30.03 | 33.10 | 40.86 | i | 37.89 | b | 36.84 | 37.88 | o | 36.56 | l | 31.71 | 12.70 | 24.87 | 26.03 | |||||||||
| 1994 | 26.94 | 21.96 | 25.26 | 32.50 | 34.65 | 37.73 | 41.55 | 38.10 | 38.60 | 29.26 | 21.47 | 24.35 | 31.03 | |||||||||||||
| 1995 | 26.06 | 29.04 | 26.29 | 27.53 | 34.87 | 40.03 | 43.32 | 38.60 | a | 38.67 | 29.74 | 32.97 | 22.74 | 32.49 | ||||||||||||
| 1996 | 23.23 | 20.28 | 27.00 | 31.33 | 31.87 | ----- | z | 43.71 | 42.48 | 34.10 | 29.74 | 26.43 | 25.74 | 30.54 | ||||||||||||
| 1997 | 23.90 | a | 24.11 | 27.00 | 27.87 | 34.74 | 35.20 | 40.29 | 44.06 | 38.97 | 29.61 | 29.97 | 21.35 | 31.42 | ||||||||||||
| 1998 | 24.45 | 27.21 | 27.03 | a | 28.70 | 35.29 | 38.30 | 46.39 | 41.06 | 38.47 | 28.06 | 29.97 | 22.30 | a | 32.27 | |||||||||||
| 1999 | 24.97 | 26.61 | 25.29 | 24.68 | b | 29.82 | c | 34.55 | a | 37.61 | c | 44.14 | c | 32.36 | b | 27.83 | b | 32.73 | 24.71 | 30.44 | ||||||
| 2000 | 22.03 | 26.65 | c | 24.07 | b | 30.11 | b | 35.10 | b | 37.90 | a | 40.10 | b | 38.21 | c | 36.17 | 31.52 | 20.70 | 25.48 | b | 30.67 | |||||
| 2001 | 22.67 | a | 22.04 | 25.76 | b | 25.27 | 32.07 | b | ----- | z | 41.77 | 44.21 | b | 39.67 | 30.94 | 30.41 | a | 22.42 | 30.66 | |||||||
| 2002 | 25.23 | ----- | z | 23.03 | 26.93 | 30.29 | 40.37 | 43.23 | 38.48 | ----- | z | 24.26 | 26.13 | 25.81 | 30.38 | |||||||||||
| 2003 | 31.00 | 22.50 | 30.35 | 29.43 | 32.77 | e | ----- | z | 43.16 | 43.77 | 39.30 | 34.03 | 22.70 | 24.71 | 32.16 | |||||||||||
| 2004 | 23.39 | 26.34 | 28.48 | 28.47 | 34.48 | 36.56 | e | 42.84 | 45.61 | 36.63 | 32.58 | ----- | z | 27.61 | 33.00 | |||||||||||
| 2005 | 23.35 | 21.79 | 27.19 | 31.27 | 38.94 | 35.77 | 42.13 | 39.97 | 31.90 | 32.48 | ----- | z | 19.55 | 31.30 | ||||||||||||
| 2006 | 28.06 | 18.14 | 24.32 | ----- | z | 30.20 | k | 40.83 | ----- | z | 37.90 | 33.56 | e | 27.97 | 27.83 | 22.71 | 29.04 | |||||||||
| 2007 | ----- | z | 26.18 | 28.90 | 26.93 | 31.13 | 38.00 | a | 45.42 | 39.58 | 34.60 | 31.12 | e | 25.40 | 23.61 | 31.90 | ||||||||||
| 2008 | ----- | z | 25.28 | ----- | z | ----- | z | 34.10 | 33.60 | 40.00 | 42.63 | d | 33.45 | a | 32.33 | a | 30.10 | 16.29 | 31.97 | |||||||
| 2009 | 21.03 | 23.57 | 23.23 | 24.80 | 33.45 | 40.17 | 42.87 | 42.61 | ----- | z | ----- | z | ----- | z | ----- | z | 31.47 | |||||||||
| 2010 | 29.69 | b | 27.56 | a | 23.23 | a | 26.27 | d | 32.65 | 37.50 | 40.19 | 38.29 | 38.30 | 32.71 | 23.87 | 22.55 | 31.07 | |||||||||
| 2011 | 22.73 | a | 18.29 | 27.47 | a | 24.97 | 29.52 | d | 35.44 | c | 37.28 | b | 39.10 | 38.03 | 30.97 | 21.43 | b | 20.19 | 28.78 | |||||||
| 2012 | 22.65 | 21.24 | 24.39 | 29.47 | 30.20 | a | 38.27 | 43.68 | 41.77 | 37.28 | a | 32.68 | 31.43 | 21.32 | 31.20 | |||||||||||
| 2013 | 19.94 | 23.32 | 25.71 | 29.00 | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 22.99 | ||||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 21.93 | 24.24 | 25.89 | 28.18 | 33.24 | 38.89 | 42.39 | 41.93 | 37.18 | 31.60 | 27.03 | 22.91 | 31.59 | |||||||||||||
| S.D. | 5.97 | 3.66 | 2.65 | 2.54 | 2.91 | 2.67 | 2.52 | 2.70 | 2.87 | 2.78 | 4.21 | 4.25 | 1.29 | |||||||||||||
| SKEW | -1.37 | -0.46 | -0.73 | -0.14 | 0.37 | 0.09 | -0.15 | 0.44 | -0.16 | -0.08 | -1.49 | -0.54 | 0.52 | |||||||||||||
| MAX | 33.03 | 32.75 | 31.23 | 33.10 | 39.97 | 45.57 | 47.81 | 48.58 | 42.73 | 38.45 | 33.00 | 32.23 | 35.93 | |||||||||||||
| MIN | 2.86 | 12.93 | 16.19 | 21.59 | 26.61 | 32.70 | 36.84 | 37.90 | 31.79 | 24.26 | 10.80 | 11.32 | 28.51 | |||||||||||||
| NO YRS | 60 | 61 | 59 | 58 | 59 | 60 | 63 | 63 | 57 | 63 | 63 | 62 | 37 | |||||||||||||