| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1955 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 24.57 | p | 19.39 | c | 19.39 | |
| 1956 | 15.17 | a | 10.65 | c | 22.48 | h | 32.00 | d | 42.13 | h | 42.50 | d | 54.18 | c | 52.00 | j | 43.12 | f | 30.70 | h | 21.90 | a | 18.09 | h | 29.40 | |
| 1957 | 4.71 | 16.32 | ----- | z | 32.77 | 42.42 | 46.13 | 50.58 | 50.79 | c | 45.76 | m | 33.81 | j | 20.65 | j | 21.29 | q | 34.82 | |||||||
| 1958 | 14.32 | c | 25.38 | b | 23.48 | 30.37 | 45.47 | a | ----- | z | ----- | z | ----- | z | 41.72 | a | 35.03 | 22.52 | c | 22.84 | 29.02 | |||||
| 1959 | 20.23 | a | 23.36 | c | 24.87 | h | 32.40 | e | 36.50 | g | 47.96 | f | 54.59 | d | 50.48 | d | 42.26 | c | 33.80 | f | 18.52 | e | 14.92 | f | 34.55 | |
| 1960 | 8.59 | i | 11.69 | m | 24.97 | b | 30.50 | d | 34.82 | c | 44.74 | g | 58.76 | b | 49.39 | c | 45.88 | f | 35.35 | n | 24.82 | m | 15.68 | l | 39.69 | |
| 1961 | 15.95 | i | 27.12 | k | 23.76 | n | 28.25 | f | 36.83 | m | 51.08 | e | 56.50 | i | 58.69 | e | 39.79 | a | 32.83 | b | 20.56 | e | 15.14 | q | 40.59 | |
| 1962 | 4.05 | l | 15.47 | k | 21.44 | o | 32.62 | i | 33.29 | q | 45.29 | b | 51.59 | b | 50.41 | b | 44.83 | f | 34.93 | c | 26.88 | d | 21.72 | m | 41.82 | |
| 1963 | 10.21 | g | 29.85 | a | 26.43 | h | 29.63 | c | 42.05 | i | 45.47 | m | 49.93 | d | 54.13 | 49.78 | g | 35.39 | h | 25.67 | f | 15.21 | g | 40.88 | ||
| 1964 | 11.00 | k | 11.21 | o | 20.11 | v | 27.08 | q | 34.58 | s | ----- | z | 52.30 | a | 48.19 | d | 41.40 | e | 32.78 | m | 20.00 | p | 14.15 | r | 47.30 | |
| 1965 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 45.65 | j | 51.89 | l | 48.24 | n | 38.54 | d | 34.52 | f | 27.78 | g | 16.17 | h | 38.54 | |
| 1966 | 19.73 | e | 18.62 | l | 25.48 | f | 31.00 | f | 39.27 | i | 44.04 | c | 51.85 | e | 51.60 | f | 48.59 | a | 31.56 | f | 26.05 | k | 19.50 | g | 41.05 | |
| 1967 | 19.68 | i | 23.35 | h | 25.00 | m | 29.30 | t | 41.07 | p | 46.62 | d | 55.65 | e | 56.90 | b | 48.88 | f | 31.86 | b | 26.47 | 14.55 | 38.67 | |||
| 1968 | 11.57 | c | 25.07 | 26.87 | a | 28.79 | b | 39.90 | k | 46.97 | a | 55.13 | 50.00 | d | 43.00 | a | 29.97 | b | ----- | z | ----- | z | 35.26 | |||
| 1969 | 10.21 | l | 12.64 | n | 20.58 | l | 30.59 | h | 41.46 | c | 46.15 | d | 49.77 | a | 48.30 | h | 41.73 | d | 28.76 | b | 21.43 | b | 20.77 | i | 38.22 | |
| 1970 | 17.35 | h | 25.82 | f | 25.90 | b | 26.06 | m | 37.07 | d | 49.54 | b | 52.32 | f | 53.40 | a | 37.76 | e | 28.85 | d | 26.70 | g | 14.84 | f | 38.75 | |
| 1971 | 19.04 | d | 22.17 | d | 20.05 | i | 29.45 | h | 40.81 | 43.93 | 53.75 | c | 58.00 | d | 37.46 | b | 30.96 | f | 25.16 | e | 12.60 | f | 37.54 | |||
| 1972 | 9.59 | i | 17.54 | c | 28.59 | d | 28.11 | b | 39.85 | d | 47.17 | a | 52.40 | a | 54.85 | d | 38.96 | e | 34.62 | j | ----- | z | ----- | z | 38.43 | |
| 1973 | 12.33 | p | 22.82 | q | 27.38 | g | 32.04 | e | 39.29 | g | 45.52 | e | 55.11 | c | 53.81 | d | 42.86 | i | 32.58 | g | 24.10 | i | 20.56 | o | 46.62 | |
| 1974 | 6.50 | k | 22.26 | i | 25.32 | l | 31.33 | f | 37.22 | d | 50.57 | 53.16 | 51.93 | d | 44.12 | f | 34.15 | d | 25.09 | h | 16.59 | d | 40.60 | |||
| 1975 | 12.65 | e | 16.96 | e | 22.66 | b | 26.67 | c | 35.46 | c | 44.32 | b | 56.54 | c | 48.13 | a | 41.72 | e | 33.20 | f | 21.60 | e | 18.08 | f | 32.67 | |
| 1976 | 15.86 | j | 13.80 | i | 18.55 | k | ----- | z | 38.04 | g | 42.00 | a | 54.17 | a | 48.81 | o | 44.17 | l | 31.04 | g | 21.73 | o | 14.32 | l | 48.08 | |
| 1977 | 7.62 | g | 19.75 | h | 23.23 | e | 34.20 | e | 36.26 | d | 50.07 | a | 51.50 | a | 54.71 | 42.60 | 33.94 | 23.44 | e | 23.83 | a | 37.38 | ||||
| 1978 | 18.75 | c | 23.45 | f | 30.04 | c | 33.07 | c | 35.63 | a | 45.07 | c | 52.97 | b | 49.16 | 41.07 | c | 32.17 | b | 19.00 | d | 9.65 | 33.33 | |||
| 1979 | 1.21 | g | 18.65 | k | 27.34 | b | 31.56 | c | 39.14 | c | 45.64 | e | 53.58 | 53.57 | c | 45.73 | 37.52 | d | 21.75 | b | 20.67 | d | 37.65 | |||
| 1980 | 14.04 | e | 25.12 | c | 26.72 | b | 34.57 | 41.04 | d | 42.97 | 51.73 | a | 47.23 | 42.77 | 31.84 | 23.63 | 19.62 | b | 33.44 | |||||||
| 1981 | 23.97 | 18.23 | b | 27.50 | c | 33.17 | a | 38.55 | 42.90 | 49.32 | 54.23 | e | 43.30 | 31.62 | b | 26.90 | a | 20.13 | 34.15 | |||||||
| 1982 | ----- | z | 13.82 | 26.74 | 27.40 | 36.58 | 47.30 | 50.90 | 52.61 | 41.77 | 31.00 | 19.10 | 16.42 | 33.06 | ||||||||||||
| 1983 | 18.65 | 23.86 | 29.61 | 29.50 | 39.71 | 42.60 | 49.42 | 54.00 | 40.10 | 33.58 | 26.73 | 9.03 | 33.07 | |||||||||||||
| 1984 | 11.35 | 14.07 | 25.21 | l | 29.80 | 35.90 | 42.33 | 52.97 | 52.23 | 38.60 | 28.06 | 24.13 | 5.74 | 30.47 | ||||||||||||
| 1985 | 7.61 | 9.11 | 19.35 | 34.07 | 39.48 | 45.27 | 56.03 | 46.39 | c | 30.84 | k | 27.35 | 10.37 | 0.77 | 26.89 | |||||||||||
| 1986 | 11.16 | 22.93 | 28.65 | 29.50 | 37.65 | 47.43 | 48.09 | t | 55.35 | 39.70 | 33.13 | 26.70 | 15.65 | 31.62 | ||||||||||||
| 1987 | 9.55 | 21.29 | 28.10 | 35.17 | 42.77 | 48.37 | 51.03 | 51.33 | a | 45.80 | 33.90 | 26.11 | b | 18.65 | 34.34 | |||||||||||
| 1988 | 14.19 | 17.90 | 22.68 | 33.60 | 37.94 | 48.57 | 54.65 | 51.71 | 42.70 | 39.74 | 25.83 | 14.81 | 33.69 | |||||||||||||
| 1989 | 10.45 | 7.07 | 26.06 | 34.87 | 37.87 | 47.17 | 53.32 | 49.94 | 42.73 | 32.94 | 22.93 | 16.26 | 31.80 | |||||||||||||
| 1990 | 20.13 | 17.64 | 27.90 | 36.90 | 37.29 | 46.30 | 56.29 | 55.42 | 51.33 | 31.13 | 24.07 | 14.94 | o | 36.76 | ||||||||||||
| 1991 | 11.13 | 25.29 | 26.84 | 32.60 | 37.00 | 42.30 | 54.42 | 55.45 | 44.50 | n | 34.00 | 26.17 | 18.13 | 33.03 | ||||||||||||
| 1992 | 15.39 | 25.79 | 31.58 | 35.37 | 43.42 | 51.97 | 52.00 | 54.03 | 42.50 | 34.81 | 22.30 | 10.77 | 34.99 | |||||||||||||
| 1993 | 8.16 | 8.75 | 21.67 | j | 31.53 | 42.00 | v | 42.93 | 44.90 | 47.87 | 42.33 | 34.65 | 14.93 | 17.29 | 29.34 | |||||||||||
| 1994 | 18.42 | 15.39 | 22.58 | 33.93 | 42.23 | 45.53 | 56.29 | 53.77 | 46.53 | o | ----- | z | 9.60 | y | 9.44 | v | 36.02 | |||||||||
| 1995 | 13.00 | s | 26.53 | k | ----- | z | 28.32 | e | 38.29 | 42.97 | 52.29 | 48.29 | 45.63 | 30.13 | 24.94 | n | 16.62 | r | 40.85 | |||||||
| 1996 | 15.25 | s | 6.33 | t | 21.33 | s | 31.78 | l | 34.35 | 42.00 | 52.26 | 48.23 | 39.17 | 31.55 | 24.03 | 15.13 | 35.84 | |||||||||
| 1997 | 17.74 | 20.74 | a | 25.16 | 29.70 | 40.13 | 43.73 | 49.13 | 49.94 | 43.90 | 30.90 | 24.63 | 14.77 | 32.54 | ||||||||||||
| 1998 | 16.80 | k | 20.45 | q | 28.65 | n | 31.24 | i | 39.05 | k | 42.07 | 54.94 | 51.61 | 48.40 | 30.39 | 26.17 | 13.10 | a | 38.10 | |||||||
| 1999 | 19.29 | g | 5.33 | p | 28.90 | k | 28.33 | 34.74 | 42.57 | 48.17 | a | 51.57 | c | 39.70 | 30.74 | 27.90 | 13.61 | m | 37.97 | |||||||
| 2000 | 15.46 | e | ----- | z | 23.20 | f | 33.07 | 38.00 | 44.03 | a | 49.40 | a | 51.39 | 39.97 | a | 33.10 | 18.00 | f | 14.50 | i | 38.05 | |||||
| 2001 | 10.70 | d | 15.36 | f | 27.96 | c | ----- | z | 38.47 | a | 43.03 | a | 52.23 | 53.81 | 44.67 | 31.13 | a | 24.97 | a | 9.07 | q | 36.33 | ||||
| 2002 | ----- | z | ----- | z | 25.20 | z | 31.80 | 36.26 | 47.03 | 55.06 | 46.26 | 41.90 | 27.23 | a | 21.00 | 20.97 | 36.39 | |||||||||
| 2003 | 22.29 | 22.79 | 29.87 | 30.00 | 37.68 | 45.20 | 56.71 | 53.52 | 44.10 | 34.48 | 19.63 | 22.42 | e | 34.89 | ||||||||||||
| 2004 | 5.42 | g | 0.64 | g | 16.71 | 32.53 | 38.87 | 45.47 | 52.00 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 37.12 | ||||||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 14.69 | 19.12 | 26.04 | 31.65 | 38.57 | 45.46 | 52.79 | 51.97 | 42.32 | 32.28 | 22.95 | 15.89 | 33.66 | |||||||||||||
| S.D. | 4.84 | 6.02 | 3.39 | 2.52 | 2.66 | 2.67 | 2.70 | 3.07 | 3.09 | 2.73 | 3.76 | 5.47 | 1.07 | |||||||||||||
| SKEW | -0.03 | -0.39 | -0.91 | -0.06 | 0.60 | 0.62 | -0.37 | 0.05 | 0.87 | 0.33 | -1.34 | -0.95 | -0.35 | |||||||||||||
| MAX | 23.97 | 29.85 | 31.58 | 36.90 | 45.47 | 51.97 | 58.76 | 58.69 | 51.33 | 39.74 | 27.90 | 23.83 | 34.99 | |||||||||||||
| MIN | 4.71 | 7.07 | 16.71 | 26.67 | 34.35 | 42.00 | 44.90 | 46.26 | 37.46 | 27.23 | 10.37 | 0.77 | 31.80 | |||||||||||||
| NO YRS | 27 | 26 | 26 | 35 | 35 | 43 | 44 | 42 | 36 | 34 | 33 | 25 | 9 | |||||||||||||