| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1948 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 57.68 | 50.90 | d | 40.29 | e | 21.02 | h | 11.72 | b | 40.15 | ||
| 1949 | -0.64 | b | 16.30 | 27.50 | b | 37.39 | l | 47.28 | a | 51.42 | 58.88 | b | 59.18 | 49.29 | i | 33.35 | d | 32.34 | e | 17.54 | d | 34.32 | ||||
| 1950 | 12.76 | 22.76 | a | 24.25 | c | 36.26 | m | 39.64 | c | 49.50 | b | 54.84 | 54.84 | 50.08 | l | 41.62 | e | 26.33 | a | 21.38 | c | 34.79 | ||||
| 1951 | 10.69 | 21.78 | a | 27.18 | q | 35.35 | f | 45.78 | f | 46.56 | e | 57.40 | 55.13 | 46.54 | d | 34.85 | e | 21.68 | e | 12.05 | c | 34.08 | ||||
| 1952 | 12.30 | d | 16.34 | a | 21.13 | a | 38.91 | h | 45.19 | g | 52.29 | a | 55.42 | 56.19 | 51.93 | 41.85 | h | 20.65 | c | 20.27 | c | 34.06 | ||||
| 1953 | 27.55 | a | 20.91 | 29.28 | a | 31.58 | d | 45.35 | h | 51.35 | 61.31 | 58.92 | 51.25 | d | 42.31 | d | 30.42 | f | 16.22 | d | 39.07 | |||||
| 1954 | 19.62 | a | 24.94 | a | 22.62 | a | 36.77 | d | 45.07 | h | 48.00 | 60.35 | 55.44 | 49.68 | h | 34.48 | h | 28.18 | h | 14.46 | f | 38.25 | ||||
| 1955 | 10.67 | b | 13.52 | 17.35 | a | 32.69 | d | 43.24 | h | 49.59 | a | 58.52 | 60.39 | 48.46 | c | 40.09 | i | 20.58 | e | 15.46 | e | 32.72 | ||||
| 1956 | 19.32 | 12.28 | 24.66 | 36.50 | d | 47.82 | i | 53.81 | c | 59.08 | 55.76 | 49.76 | c | 37.94 | e | 13.33 | r | 15.11 | 36.42 | |||||||
| 1957 | 3.25 | a | 22.07 | 26.05 | 33.73 | 46.00 | 51.68 | 57.89 | 57.40 | b | 46.30 | g | 38.45 | 20.11 | c | 20.09 | n | 35.66 | ||||||||
| 1958 | 15.73 | g | 25.46 | 21.86 | j | 32.73 | 48.93 | a | 51.88 | d | 54.85 | 59.24 | 49.34 | b | 41.08 | 25.57 | 20.67 | m | 43.23 | |||||||
| 1959 | 18.34 | i | 15.98 | 24.82 | 34.61 | b | 41.50 | 54.92 | 60.02 | 58.21 | 48.58 | 38.05 | 19.70 | h | 16.54 | d | 39.32 | |||||||||
| 1960 | 16.00 | d | 12.70 | b | 20.85 | k | 35.70 | 43.68 | a | 52.29 | b | 60.23 | 56.73 | 50.39 | c | 39.00 | k | 23.35 | g | 14.27 | c | 38.00 | ||||
| 1961 | 13.10 | g | 25.29 | b | 29.50 | b | 34.15 | 45.02 | b | 55.78 | 59.71 | 60.48 | 43.43 | b | 36.22 | b | 22.55 | 13.13 | 38.66 | |||||||
| 1962 | 3.42 | 18.71 | b | 24.02 | b | 36.37 | 45.88 | c | 52.03 | 56.29 | 55.61 | 49.65 | 42.20 | a | 29.21 | b | 19.92 | 36.11 | ||||||||
| 1963 | 4.15 | d | 25.44 | b | 25.93 | c | 34.40 | 45.44 | 51.28 | 58.10 | 59.00 | 54.00 | a | 42.61 | c | 28.33 | 16.83 | y | 38.97 | |||||||
| 1964 | 12.90 | a | 11.50 | 18.61 | 34.08 | d | 43.47 | 49.53 | 59.58 | 54.31 | 45.74 | i | 40.20 | k | 20.84 | h | 14.60 | f | 35.50 | |||||||
| 1965 | 17.23 | 14.33 | e | 13.58 | 36.30 | b | 40.71 | 49.39 | c | 55.97 | 53.69 | 39.14 | a | 39.81 | 28.84 | b | 18.38 | b | 33.95 | |||||||
| 1966 | 15.02 | 15.92 | c | 30.03 | m | 34.11 | b | 47.48 | c | 49.97 | 61.27 | 57.13 | 51.78 | e | 36.38 | a | 28.64 | i | 17.28 | f | 41.01 | |||||
| 1967 | 20.77 | i | 22.50 | g | 20.88 | s | 32.38 | b | 42.40 | b | 50.75 | 58.58 | 58.32 | 52.60 | 42.17 | p | 27.67 | i | 9.61 | 43.52 | ||||||
| 1968 | 11.52 | 21.41 | 29.55 | 31.77 | 41.75 | s | 51.32 | 59.13 | 54.37 | 48.03 | 40.05 | 20.32 | 14.13 | 34.69 | ||||||||||||
| 1969 | 18.87 | 21.34 | 22.13 | 39.07 | 47.31 | 49.27 | 58.13 | 60.37 | 52.37 | 33.63 | 24.30 | 17.16 | 36.99 | |||||||||||||
| 1970 | 18.65 | a | 22.89 | j | 24.12 | f | 28.58 | d | 44.94 | 54.08 | 59.55 | 60.34 | 44.47 | 34.58 | 30.88 | v | 15.55 | 40.08 | ||||||||
| 1971 | 17.89 | 18.45 | 23.16 | ----- | z | 47.66 | b | 52.41 | s | 56.56 | 61.05 | 45.07 | 36.48 | 24.50 | 8.50 | t | 36.76 | |||||||||
| 1972 | 14.75 | i | 21.67 | 33.58 | e | 36.42 | 44.97 | b | 52.43 | 55.08 | 57.95 | 46.53 | a | 37.59 | b | 24.12 | 7.93 | c | 38.02 | |||||||
| 1973 | 10.00 | d | 18.91 | 26.92 | 32.36 | a | 43.68 | 52.60 | a | 58.92 | 57.81 | 48.42 | 40.71 | 26.53 | a | 21.34 | b | 36.52 | ||||||||
| 1974 | 18.28 | f | 21.91 | a | 28.97 | b | 37.39 | c | 45.52 | i | 55.25 | 60.87 | 55.65 | 49.50 | a | 41.87 | d | 26.86 | h | 18.18 | q | 43.92 | ||||
| 1975 | 5.64 | t | 17.27 | f | 24.61 | q | 26.56 | m | 42.05 | c | 49.82 | 60.77 | 56.03 | 51.90 | 38.73 | 17.75 | f | 29.17 | y | 49.88 | ||||||
| 1976 | 19.05 | l | 20.10 | h | 25.50 | m | 37.11 | u | 47.04 | c | 55.17 | r | 60.69 | 56.38 | j | 47.41 | s | 35.90 | 27.87 | g | 10.79 | x | 47.88 | |||
| 1977 | 9.20 | i | 18.08 | o | 25.79 | l | 37.95 | i | 43.95 | c | 54.83 | 57.64 | i | 55.50 | z | 51.06 | u | 37.38 | z | 26.12 | v | 11.58 | s | 49.39 | ||
| 1978 | 16.86 | m | 20.57 | m | 33.25 | m | 36.39 | h | 42.09 | b | 50.60 | 55.69 | g | 53.38 | n | ----- | z | ----- | z | 15.73 | q | 7.97 | p | 46.34 | ||
| 1979 | 0.04 | c | 21.88 | d | 26.63 | e | 34.10 | e | 45.65 | h | 51.21 | d | 58.52 | b | 57.88 | b | 50.31 | f | 40.44 | e | 16.14 | i | 18.02 | i | 36.34 | |
| 1980 | 9.47 | m | 21.28 | m | 26.30 | u | 37.37 | c | 46.94 | e | 54.25 | l | 59.37 | 54.40 | b | ----- | z | 41.90 | p | 26.17 | 22.98 | d | 41.20 | |||
| 1981 | 19.46 | d | 19.22 | e | 31.05 | i | ----- | z | ----- | z | ----- | z | ----- | z | 60.21 | ----- | z | ----- | z | ----- | z | 17.78 | f | 32.96 | ||
| 1982 | 12.07 | k | ----- | z | ----- | z | ----- | z | ----- | z | 50.17 | 55.14 | c | ----- | z | ----- | z | ----- | z | 20.45 | 16.11 | 35.47 | ||||
| 1983 | ----- | z | 22.41 | 30.61 | h | 32.42 | ----- | z | 48.16 | k | 54.61 | 56.32 | 46.65 | 40.47 | 27.02 | 5.21 | 35.64 | |||||||||
| 1984 | 10.74 | 15.32 | a | 27.89 | 33.12 | 41.73 | ----- | z | 59.55 | 57.61 | d | 44.20 | 32.97 | 23.42 | 9.19 | 32.34 | ||||||||||
| 1985 | 8.08 | 8.32 | 21.77 | 37.03 | 46.21 | 52.48 | 60.06 | 53.77 | 43.62 | 35.05 | 16.90 | 8.58 | 32.66 | |||||||||||||
| 1986 | 16.06 | 22.18 | 32.47 | 38.30 | j | 43.90 | 55.75 | ----- | z | 57.52 | 44.27 | 38.13 | 20.91 | a | 9.55 | 34.07 | ||||||||||
| 1987 | 10.13 | 19.00 | 27.16 | 39.48 | 48.19 | 52.27 | 55.52 | 54.76 | 50.00 | 38.74 | 25.90 | 13.95 | 36.26 | |||||||||||||
| 1988 | 9.90 | 19.03 | 23.77 | 36.52 | 44.92 | 57.63 | 60.90 | 56.19 | 46.37 | 44.48 | 23.77 | 11.61 | 36.26 | |||||||||||||
| 1989 | 11.97 | 8.18 | 26.71 | 35.79 | b | 43.76 | 51.98 | 61.00 | 55.61 | 48.72 | 38.56 | 26.92 | 12.66 | 35.15 | ||||||||||||
| 1990 | 16.06 | 15.16 | 27.24 | 38.63 | 41.55 | 51.21 | a | 57.89 | 58.31 | 54.05 | 36.90 | 28.00 | 1.85 | 35.57 | ||||||||||||
| 1991 | 11.61 | 24.95 | 25.79 | 33.88 | 43.34 | 52.82 | 59.18 | 59.68 | 48.23 | 35.48 | 18.33 | 12.23 | 35.46 | |||||||||||||
| 1992 | 13.32 | 24.10 | 33.23 | 40.07 | 48.34 | 52.22 | 53.21 | 55.02 | 46.15 | 39.77 | 19.77 | 11.55 | 36.39 | |||||||||||||
| 1993 | 11.50 | 13.62 | 29.02 | 35.08 | 47.77 | 49.62 | 51.26 | 53.60 | 46.95 | 38.74 | 18.85 | 15.23 | 34.27 | |||||||||||||
| 1994 | 20.44 | 13.91 | 29.31 | 37.42 | 48.19 | 52.78 | 56.98 | 58.92 | 49.88 | 38.60 | 16.40 | 18.15 | 36.75 | |||||||||||||
| 1995 | 14.42 | 23.16 | 26.50 | 34.92 | 42.98 | 53.25 | 60.68 | 59.52 | 49.87 | 35.55 | 28.95 | 19.68 | 37.46 | |||||||||||||
| 1996 | 12.03 | 16.67 | 23.55 | 36.43 | 42.02 | 54.25 | 60.08 | 57.84 | 45.95 | 36.73 | 24.50 | 15.77 | 35.49 | |||||||||||||
| 1997 | 10.74 | 13.96 | 24.71 | 28.95 | 45.66 | 56.75 | 60.34 | 59.08 | 52.02 | 38.47 | 26.17 | 13.73 | 35.88 | |||||||||||||
| 1998 | 18.13 | 20.89 | 27.03 | 36.90 | 45.75 | a | 47.07 | 62.00 | 59.81 | 53.85 | ----- | z | 28.32 | 13.65 | 37.58 | |||||||||||
| 1999 | 17.61 | 19.21 | 25.85 | 32.28 | 41.90 | 48.82 | 55.10 | a | 58.16 | 42.68 | 37.81 | b | 30.05 | 13.53 | 35.25 | |||||||||||
| 2000 | 14.47 | 20.60 | 24.00 | 35.09 | b | 42.95 | a | 48.58 | 56.90 | 56.29 | 47.90 | 39.93 | b | 15.67 | a | 14.00 | 34.70 | |||||||||
| 2001 | 11.32 | 17.38 | 29.79 | 36.42 | 46.50 | 53.67 | 61.31 | 61.48 | 52.93 | 37.84 | 30.37 | 15.02 | 37.83 | |||||||||||||
| 2002 | 14.58 | 14.32 | 22.21 | 35.68 | 43.11 | 53.32 | 62.79 | 55.23 | 50.17 | 32.23 | 22.00 | 18.79 | 35.37 | |||||||||||||
| 2003 | 18.98 | 15.71 | 27.98 | 36.82 | 44.45 | 49.88 | 62.24 | 61.11 | 47.30 | 40.66 | 18.77 | 18.71 | 36.89 | |||||||||||||
| 2004 | 14.84 | 18.12 | 33.37 | 40.77 | 44.74 | 52.43 | 59.60 | 56.73 | 48.68 | 39.13 | 25.80 | 21.16 | 37.95 | |||||||||||||
| 2005 | 17.85 | 18.34 | 28.73 | 36.23 | 44.56 | 50.38 | 60.34 | 56.63 | 47.88 | 40.69 | 25.63 | ----- | z | 38.84 | ||||||||||||
| 2006 | 18.69 | 14.61 | ----- | z | 37.72 | a | 45.52 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 29.14 | ||||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 13.43 | 18.40 | 26.01 | 35.23 | 44.70 | 51.78 | 58.54 | 57.39 | 48.53 | 38.31 | 24.02 | 14.67 | 35.87 | |||||||||||||
| S.D. | 5.59 | 4.39 | 4.11 | 2.63 | 2.30 | 2.39 | 2.51 | 2.16 | 3.29 | 2.78 | 4.16 | 4.47 | 1.28 | |||||||||||||
| SKEW | -0.46 | -0.29 | -0.56 | -0.31 | -0.06 | 0.21 | -0.72 | 0.05 | -0.45 | -0.20 | -0.16 | -0.50 | -0.54 | |||||||||||||
| MAX | 27.55 | 25.46 | 33.58 | 40.77 | 48.93 | 57.63 | 62.79 | 61.48 | 54.05 | 44.48 | 32.34 | 22.98 | 37.95 | |||||||||||||
| MIN | -0.64 | 8.18 | 13.58 | 28.58 | 39.64 | 46.56 | 51.26 | 53.60 | 39.14 | 32.23 | 15.67 | 1.85 | 32.66 | |||||||||||||
| NO YRS | 45 | 50 | 43 | 46 | 46 | 51 | 53 | 54 | 46 | 46 | 41 | 43 | 22 | |||||||||||||