| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1956 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 34.84 | b | 28.39 | d | 31.61 | |
| 1957 | 17.55 | j | 37.83 | m | 41.09 | b | 44.21 | b | 53.84 | 64.44 | c | 68.13 | e | 62.93 | b | 57.34 | k | 46.42 | 33.61 | c | 31.91 | c | 49.62 | |||
| 1958 | 31.08 | a | 39.75 | h | 35.28 | b | 43.95 | b | ----- | z | 63.58 | r | 70.80 | c | 73.64 | i | 60.83 | x | 50.47 | b | 33.92 | e | 36.14 | c | 43.09 | |
| 1959 | 33.11 | 32.44 | b | 38.95 | 49.36 | a | 51.77 | e | 65.50 | 73.60 | 67.57 | b | 57.68 | 50.31 | 36.85 | 27.41 | c | 48.71 | ||||||||
| 1960 | 24.29 | 31.40 | 42.07 | a | 46.09 | b | 53.64 | b | 68.54 | d | 72.60 | 66.40 | 62.52 | b | 48.68 | 38.22 | 32.18 | a | 48.88 | |||||||
| 1961 | 32.55 | 38.35 | b | 39.90 | 46.27 | 52.00 | f | 68.72 | c | 71.91 | b | 72.61 | i | 56.31 | a | 49.19 | d | 34.56 | c | 27.30 | i | 48.64 | ||||
| 1962 | 21.93 | b | 28.85 | h | 35.93 | h | 51.96 | g | 52.44 | f | 64.69 | d | 69.60 | g | 67.43 | d | 62.12 | b | ----- | z | 44.73 | d | 43.53 | k | 52.18 | |
| 1963 | 24.79 | e | 43.29 | 39.00 | g | 38.69 | a | 52.38 | g | 58.22 | a | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 41.25 | ||
| 1964 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1965 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 1966 | ----- | z | ----- | z | ----- | z | ----- | z | 57.47 | k | 65.14 | p | 68.33 | h | 69.48 | d | 60.88 | e | ----- | z | 38.80 | e | 29.67 | d | 49.71 | |
| 1967 | 27.96 | e | 34.59 | e | 36.94 | d | ----- | z | 55.98 | f | 60.77 | d | 71.98 | d | ----- | z | 64.83 | d | 48.19 | e | ----- | z | ----- | z | 49.32 | |
| 1968 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 65.25 | f | 73.05 | 62.81 | 60.13 | 50.45 | c | 38.75 | 26.84 | 52.00 | ||||||
| 1969 | 28.11 | 29.38 | 36.63 | 46.93 | 59.25 | a | 62.68 | 71.11 | 68.44 | 61.62 | d | 42.06 | 37.65 | 31.05 | 47.91 | |||||||||||
| 1970 | 32.16 | 38.20 | 38.15 | 39.65 | ----- | z | 63.23 | 70.03 | 68.74 | 55.13 | 44.47 | ----- | z | 27.58 | a | 47.73 | ||||||||||
| 1971 | 31.65 | 35.70 | 37.37 | 44.27 | 51.90 | 59.02 | 70.63 | 70.00 | 55.10 | 43.89 | 36.40 | 22.92 | 46.57 | |||||||||||||
| 1972 | 24.52 | 34.78 | 44.00 | a | 43.97 | 57.40 | 66.17 | 71.18 | c | 66.11 | l | 53.67 | i | 48.31 | 38.10 | ----- | z | 47.60 | ||||||||
| 1973 | 23.56 | n | 35.55 | 38.10 | 46.00 | ----- | z | ----- | z | 73.43 | b | 67.84 | ----- | z | ----- | z | 37.35 | 34.92 | e | 47.60 | ||||||
| 1974 | 28.58 | 32.73 | 41.60 | 44.07 | 52.68 | 67.72 | 68.57 | b | 67.48 | c | ----- | z | ----- | z | ----- | z | ----- | z | 50.43 | |||||||
| 1975 | ----- | z | ----- | z | ----- | z | 40.03 | o | 52.37 | a | 61.50 | g | 73.32 | l | 65.96 | d | ----- | z | 47.20 | a | ----- | z | 27.73 | k | 55.18 | |
| 1976 | 28.02 | b | 36.45 | a | 37.64 | b | 45.06 | d | 57.87 | a | 59.70 | e | 70.94 | 63.45 | c | 60.80 | 48.53 | a | ----- | z | 27.54 | e | 48.73 | |||
| 1977 | 19.63 | a | 36.33 | b | 35.48 | c | 49.71 | b | 48.18 | 67.66 | a | 70.12 | c | 70.57 | b | 58.82 | b | 50.61 | c | 37.02 | a | 32.91 | d | 48.09 | ||
| 1978 | 33.48 | b | 36.11 | ----- | z | 44.95 | b | 52.31 | 61.26 | a | 69.90 | b | 66.81 | 57.29 | d | 51.97 | b | 33.78 | a | 24.12 | c | 48.36 | ||||
| 1979 | 21.90 | 33.13 | a | 41.89 | d | 46.89 | g | 56.71 | 64.33 | c | 71.19 | e | ----- | z | 61.09 | g | 51.87 | a | 33.16 | e | 27.74 | d | 44.66 | |||
| 1980 | 29.31 | b | 37.58 | d | 36.73 | g | 48.52 | a | 54.65 | d | 56.90 | f | 69.36 | f | 66.63 | 60.55 | b | 50.34 | b | ----- | z | 33.87 | l | 49.65 | ||
| 1981 | 32.84 | c | 36.33 | d | 39.55 | b | 47.70 | j | 52.73 | a | 64.78 | c | 69.64 | m | 71.72 | m | 62.90 | d | 45.52 | e | 40.04 | c | 34.11 | d | 45.42 | |
| 1982 | 23.60 | 30.95 | 37.44 | 43.64 | i | 52.48 | 61.12 | 68.16 | ----- | z | 57.30 | 46.87 | 33.67 | 29.12 | r | 45.73 | ||||||||||
| 1983 | 32.47 | 37.04 | b | 40.34 | 42.13 | 53.00 | 59.60 | 66.13 | 69.50 | 61.16 | a | 51.03 | 37.05 | 29.76 | 48.27 | |||||||||||
| 1984 | 18.21 | 29.09 | 39.95 | 43.15 | 55.61 | 59.30 | ----- | z | 70.34 | 59.30 | 44.42 | 37.33 | a | 26.07 | j | 45.67 | ||||||||||
| 1985 | 24.77 | 28.09 | 35.65 | 50.15 | 55.37 | 68.50 | a | 74.05 | l | 65.69 | j | 54.70 | 47.24 | 29.22 | 21.32 | t | 43.74 | |||||||||
| 1986 | 35.32 | 40.37 | a | 44.85 | n | 46.93 | 55.42 | 69.71 | w | 70.00 | t | 73.93 | p | 54.95 | 52.10 | j | 38.32 | b | 29.61 | m | 45.22 | |||||
| 1987 | 23.79 | 37.34 | 40.02 | 52.63 | 58.44 | 66.15 | 67.95 | 71.70 | a | 64.72 | 56.27 | 39.85 | 29.90 | 50.73 | ||||||||||||
| 1988 | 25.00 | a | 36.53 | 41.60 | 50.68 | e | 55.58 | 68.02 | 75.77 | 72.26 | 61.23 | 58.24 | 38.30 | j | 26.58 | 51.95 | ||||||||||
| 1989 | 20.61 | 23.64 | 42.77 | 52.10 | 56.00 | 66.28 | 72.87 | 67.22 | a | 61.78 | 49.77 | 37.65 | 30.52 | 48.44 | ||||||||||||
| 1990 | 31.44 | 29.43 | 43.19 | 54.55 | 53.97 | 64.63 | 74.18 | 71.85 | 66.73 | 51.19 | 36.53 | 18.13 | 49.65 | |||||||||||||
| 1991 | 27.13 | 41.02 | 39.06 | 45.83 | 51.42 | a | 60.20 | 73.34 | 72.05 | 64.55 | 52.31 | 40.73 | 30.37 | 49.83 | ||||||||||||
| 1992 | 31.82 | 40.12 | 44.97 | 53.38 | 64.81 | 66.28 | 70.65 | 72.08 | 63.62 | 54.15 | 37.50 | 26.29 | 52.14 | |||||||||||||
| 1993 | 18.21 | 26.50 | 45.55 | a | 47.42 | 59.34 | 59.82 | 64.71 | 67.47 | 61.88 | 51.76 | 32.19 | a | 30.37 | 47.10 | |||||||||||
| 1994 | 33.34 | 31.25 | 45.56 | 49.75 | 58.29 | 65.16 | a | 75.44 | 72.27 | 64.32 | 49.10 | g | 29.28 | 22.63 | 49.75 | |||||||||||
| 1995 | 33.48 | 43.27 | 40.78 | a | ----- | z | 54.32 | 60.42 | 69.68 | 70.28 | h | 63.03 | 51.25 | e | 43.64 | b | 33.97 | 49.38 | ||||||||
| 1996 | 31.39 | 34.42 | e | 41.95 | a | 47.52 | 52.73 | r | 64.63 | c | 74.00 | 71.50 | 59.80 | 50.02 | 40.70 | 34.68 | 50.05 | |||||||||
| 1997 | 30.35 | 35.62 | 44.03 | 46.15 | ----- | z | 62.80 | 70.67 | a | 71.05 | 62.82 | 49.55 | i | 40.90 | 29.56 | 49.40 | ||||||||||
| 1998 | 35.18 | 34.00 | 41.06 | 45.38 | 52.29 | ----- | z | 75.56 | 73.55 | 64.62 | 48.42 | 37.78 | 26.32 | 48.56 | ||||||||||||
| 1999 | 33.10 | f | 37.06 | d | 41.64 | f | 44.31 | f | 55.07 | d | 66.26 | e | 72.79 | e | 71.08 | f | 61.20 | c | 51.79 | c | 41.10 | e | 29.73 | e | 51.88 | |
| 2000 | 31.26 | 36.50 | 41.26 | b | 51.22 | c | 55.14 | j | 64.48 | e | 71.23 | c | 71.24 | h | 60.30 | b | 47.90 | b | 31.65 | f | 30.00 | s | 50.52 | |||
| 2001 | 25.52 | c | 31.88 | d | 43.60 | a | 45.30 | e | 60.40 | a | 62.84 | k | 66.44 | e | 70.02 | b | 61.16 | a | 52.56 | d | 36.83 | d | 26.59 | d | 47.30 | |
| 2002 | 28.45 | 35.20 | 36.26 | 48.42 | 53.75 | i | 65.93 | j | 74.44 | 66.75 | c | ----- | z | 46.85 | 37.03 | 33.65 | 45.23 | |||||||||
| 2003 | 39.08 | 32.64 | 43.31 | 42.75 | j | 60.76 | j | 66.85 | 74.58 | 69.98 | 61.44 | e | 53.76 | 32.03 | 30.98 | c | 50.47 | |||||||||
| 2004 | 24.35 | 26.88 | i | 46.31 | 50.10 | 54.10 | f | 65.58 | 72.85 | ----- | z | 60.17 | d | 48.90 | a | 36.18 | 30.44 | 48.32 | ||||||||
| 2005 | 19.94 | f | 29.39 | 42.29 | 46.10 | 54.98 | 59.67 | 74.05 | 70.16 | f | 56.15 | ----- | z | 35.52 | 27.71 | 47.32 | ||||||||||
| 2006 | 33.11 | d | 32.45 | f | 35.63 | 44.54 | e | 56.47 | 64.67 | f | 74.34 | ----- | z | 59.33 | r | 47.88 | j | 36.02 | 24.57 | d | 43.53 | |||||
| 2007 | 25.56 | ----- | z | 45.32 | a | 47.07 | 58.77 | 66.27 | 75.52 | 70.08 | 59.00 | 47.21 | 38.43 | 26.90 | f | 53.32 | ||||||||||
| 2008 | 20.35 | e | 30.66 | g | 38.66 | 43.08 | 53.87 | 62.95 | 72.27 | 70.48 | ----- | z | 48.44 | 41.38 | e | 24.35 | 47.58 | |||||||||
| 2009 | 27.75 | g | 34.48 | 39.08 | 45.98 | 59.12 | b | 61.82 | 72.42 | ----- | z | 64.20 | 45.15 | 37.23 | 21.17 | d | 48.06 | |||||||||
| 2010 | 30.78 | f | 35.46 | 39.48 | e | ----- | z | 47.95 | 62.60 | 71.06 | 67.23 | 60.85 | 51.56 | f | 34.75 | 32.60 | 50.22 | |||||||||
| 2011 | 27.90 | a | 31.06 | b | 39.73 | a | 42.53 | a | 50.65 | a | ----- | z | ----- | z | 71.27 | a | 65.09 | b | 51.07 | b | 34.31 | a | ----- | z | 45.96 | |
| 2012 | 30.57 | b | 34.04 | d | 42.95 | 48.03 | ----- | z | 63.38 | 73.32 | 69.74 | 63.71 | a | 48.39 | 39.47 | 28.02 | 49.24 | |||||||||
| 2013 | 13.48 | 33.96 | 43.00 | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 23.72 | |||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 27.86 | 34.50 | 40.50 | 46.71 | 54.97 | 63.81 | 71.67 | 68.94 | 60.85 | 49.38 | 36.97 | 28.86 | 48.86 | |||||||||||||
| S.D. | 5.40 | 4.11 | 3.01 | 3.47 | 3.42 | 3.01 | 2.62 | 2.68 | 3.08 | 3.23 | 3.24 | 3.99 | 1.54 | |||||||||||||
| SKEW | -0.45 | -0.19 | 0.04 | 0.13 | 0.39 | -0.16 | -0.62 | -0.57 | -0.40 | 0.24 | -0.14 | -0.44 | 0.61 | |||||||||||||
| MAX | 39.08 | 43.29 | 46.31 | 54.55 | 64.81 | 68.72 | 75.77 | 73.55 | 66.73 | 58.24 | 44.73 | 36.14 | 52.14 | |||||||||||||
| MIN | 13.48 | 23.64 | 35.28 | 38.69 | 47.95 | 58.22 | 64.71 | 62.81 | 54.70 | 42.06 | 29.22 | 18.13 | 46.57 | |||||||||||||
| NO YRS | 46 | 45 | 45 | 42 | 38 | 42 | 44 | 37 | 43 | 43 | 46 | 40 | 12 | |||||||||||||