| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1959 | ----- | z | ----- | z | ----- | z | 47.32 | 48.40 | 63.35 | 69.78 | a | 64.82 | c | 54.22 | 46.73 | i | 36.45 | 24.40 | 51.09 | |||||||
| 1960 | 22.50 | 29.66 | 40.66 | 45.22 | 50.23 | 62.52 | c | 71.23 | 63.73 | c | 59.18 | 47.02 | 35.67 | 27.55 | 46.26 | |||||||||||
| 1961 | 30.40 | 37.80 | 38.75 | a | 44.29 | b | 51.05 | a | 65.76 | c | 69.47 | a | 70.12 | b | 52.37 | 45.70 | d | 33.83 | a | 27.82 | a | 47.28 | ||||
| 1962 | 18.91 | d | 30.11 | 36.39 | d | 48.52 | a | 49.68 | 59.41 | a | 63.48 | c | 64.04 | h | 59.74 | k | 47.58 | 39.07 | 32.47 | a | 42.56 | |||||
| 1963 | 26.08 | 41.32 | 37.98 | 40.53 | 54.77 | a | 58.17 | c | 63.97 | 64.61 | 62.11 | c | 51.31 | 38.43 | 28.24 | 47.29 | ||||||||||
| 1964 | 28.31 | 30.67 | 34.91 | c | 42.95 | a | 51.13 | 57.65 | 68.32 | 63.92 | a | 55.36 | a | 49.18 | 34.28 | a | 31.73 | a | 45.70 | |||||||
| 1965 | 30.88 | a | 36.25 | 37.35 | 47.32 | 50.44 | 59.35 | 65.58 | 63.30 | a | 52.88 | b | 50.60 | b | 39.07 | 26.30 | c | 46.61 | ||||||||
| 1966 | 27.84 | 31.04 | 38.66 | b | 45.75 | 55.33 | a | 58.37 | 66.10 | b | 66.45 | c | 60.50 | 47.67 | a | 39.80 | 30.93 | b | 47.37 | |||||||
| 1967 | 33.94 | 36.37 | a | 37.09 | b | 37.65 | 53.02 | a | 60.23 | 70.74 | 69.77 | 62.40 | 47.02 | 39.17 | 26.95 | 47.86 | ||||||||||
| 1968 | 28.50 | 38.71 | 40.87 | 42.03 | 52.10 | 60.47 | 69.18 | 62.16 | 57.23 | 46.32 | 37.28 | 30.21 | 47.09 | |||||||||||||
| 1969 | 29.60 | 28.82 | 35.98 | 46.37 | 57.13 | d | 60.82 | 66.95 | 65.97 | 61.05 | b | 41.66 | b | 35.82 | 32.94 | 46.92 | ||||||||||
| 1970 | 32.94 | 37.59 | 37.97 | 38.93 | 53.26 | 62.27 | 69.74 | 67.73 | 53.50 | 44.05 | a | 38.63 | 26.81 | 46.95 | ||||||||||||
| 1971 | 31.90 | 34.20 | 34.84 | 43.97 | a | 53.27 | a | 58.07 | a | 67.58 | 69.79 | 52.32 | 44.26 | b | 36.13 | 27.53 | 46.15 | |||||||||
| 1972 | 25.98 | 33.33 | 42.90 | 42.98 | 54.79 | 60.69 | a | 66.90 | 66.45 | 51.03 | 45.42 | 35.53 | 21.97 | 45.67 | ||||||||||||
| 1973 | 26.98 | 33.88 | 36.58 | 42.66 | a | 55.07 | b | 60.98 | a | 66.98 | a | 67.36 | f | 57.38 | 47.34 | i | 39.50 | 34.39 | i | 46.67 | ||||||
| 1974 | 28.28 | b | 34.39 | i | 37.31 | d | 43.98 | d | 50.80 | h | 66.71 | p | 61.89 | q | 63.84 | o | 57.41 | m | 45.53 | m | 36.38 | j | 31.26 | n | 36.52 | |
| 1975 | 25.20 | a | 30.10 | g | 35.08 | 36.34 | h | 53.25 | q | 58.83 | f | 70.60 | f | 62.41 | d | 57.12 | f | 46.98 | i | 32.21 | k | 34.39 | i | 40.90 | ||
| 1976 | 30.16 | b | 33.24 | f | 33.07 | d | 42.32 | b | 54.73 | c | 55.15 | f | 67.26 | f | 61.12 | c | 59.43 | a | 46.04 | e | 36.88 | i | 26.66 | f | 46.70 | |
| 1977 | 18.54 | f | 34.56 | d | 34.97 | a | 48.78 | c | 47.19 | d | 65.45 | h | 65.19 | e | 69.44 | n | 58.30 | h | 47.93 | q | 34.85 | f | 31.77 | e | 43.74 | |
| 1978 | 33.27 | r | 35.24 | e | 43.72 | a | 43.32 | 49.90 | 58.27 | b | 66.42 | 63.85 | 53.96 | c | 47.09 | d | 31.88 | 23.14 | b | 46.98 | ||||||
| 1979 | 17.39 | 31.16 | l | 40.22 | a | 43.27 | d | 53.56 | e | 62.16 | h | 67.57 | d | 64.30 | i | 61.92 | l | 49.84 | b | 31.78 | 32.40 | b | 42.00 | |||
| 1980 | 27.81 | b | 36.18 | g | 36.83 | s | 47.08 | d | 52.00 | c | 55.73 | f | 67.05 | 62.91 | b | 58.13 | c | 44.38 | e | 37.43 | c | 29.97 | 47.42 | |||
| 1981 | 31.81 | 32.38 | c | 39.06 | 47.80 | c | 51.31 | 58.68 | 65.31 | 68.03 | 57.88 | 43.67 | e | 37.93 | 32.68 | a | 47.21 | |||||||||
| 1982 | 23.76 | 30.52 | 36.76 | 40.63 | 51.02 | 59.73 | 64.45 | c | 65.79 | 54.52 | 45.32 | 30.93 | 26.97 | 44.20 | ||||||||||||
| 1983 | 32.26 | 36.50 | 39.95 | 41.37 | 52.97 | 57.95 | 63.27 | 66.58 | 55.85 | 48.35 | 38.55 | 24.53 | 46.51 | |||||||||||||
| 1984 | 19.63 | 26.50 | j | 38.31 | 41.45 | 52.52 | 56.67 | 69.08 | 66.12 | a | 54.10 | f | 42.68 | c | 36.65 | c | 23.19 | d | 44.63 | |||||||
| 1985 | 19.75 | c | 25.54 | b | 32.20 | a | 46.72 | 52.89 | 61.74 | a | 71.35 | 62.42 | 50.05 | 40.58 | m | 21.74 | e | 10.08 | a | 41.32 | ||||||
| 1986 | 29.00 | o | 33.35 | r | 42.88 | n | 41.91 | c | 53.05 | i | 63.73 | h | 62.56 | 69.03 | k | ----- | z | 53.82 | q | 44.20 | y | 26.97 | n | 52.24 | ||
| 1987 | 25.95 | 35.88 | c | 37.79 | 45.63 | o | 52.12 | n | 60.56 | m | 63.44 | 64.68 | 57.00 | p | 50.21 | j | 37.92 | j | 29.30 | k | 45.55 | |||||
| 1988 | 26.43 | x | 33.04 | b | 37.93 | p | 48.03 | o | 51.24 | l | 61.71 | b | 67.36 | m | 64.16 | l | 55.08 | 52.07 | i | 37.22 | l | 29.80 | u | 49.94 | ||
| 1989 | 22.25 | k | ----- | z | 41.03 | o | 48.95 | 52.32 | 63.15 | 67.47 | 62.31 | 57.93 | 45.05 | l | 35.63 | c | 29.81 | 52.20 | ||||||||
| 1990 | 32.69 | 30.30 | 39.97 | 51.37 | 50.03 | 61.07 | 70.23 | 65.35 | 62.08 | 47.68 | 36.97 | a | 20.74 | 47.37 | ||||||||||||
| 1991 | 27.56 | 39.05 | 37.98 | i | 41.45 | k | 49.90 | 55.70 | o | ----- | z | 66.93 | i | 59.05 | 47.44 | 36.42 | k | 30.66 | 42.28 | |||||||
| 1992 | 30.76 | 38.45 | 43.16 | 49.13 | 58.24 | 62.48 | 64.45 | 66.40 | 57.83 | 48.69 | 32.95 | 25.73 | 48.19 | |||||||||||||
| 1993 | 19.44 | 22.30 | 36.84 | 43.28 | 55.37 | 55.03 | 57.40 | 60.84 | 56.48 | 47.94 | 28.78 | 29.40 | 42.76 | |||||||||||||
| 1994 | 32.74 | 30.91 | 42.13 | 46.77 | 54.73 | 59.63 | 69.32 | 67.24 | 58.48 | 45.42 | 30.22 | 26.44 | 47.00 | |||||||||||||
| 1995 | 33.24 | 39.66 | 39.21 | 42.42 | ----- | z | 56.95 | 65.00 | 62.34 | 57.45 | 45.74 | 42.87 | 32.03 | 46.99 | ||||||||||||
| 1996 | 31.13 | 32.74 | 40.69 | 45.63 | 50.35 | 59.50 | 68.42 | 64.66 | 55.08 | 46.69 | 37.72 | 33.45 | 47.17 | |||||||||||||
| 1997 | 29.90 | 33.66 | 41.61 | 44.58 | 57.26 | 58.27 | 64.76 | 65.97 | 58.47 | 45.92 | 38.17 | ----- | z | 48.96 | ||||||||||||
| 1998 | 35.79 | 33.95 | 39.34 | 43.97 | 50.39 | v | 57.33 | 70.34 | 65.47 | 60.67 | 45.56 | m | 37.13 | 25.95 | 46.99 | |||||||||||
| 1999 | 30.58 | e | 31.15 | b | 38.42 | 39.97 | o | 50.27 | i | 56.62 | q | 67.28 | o | 63.85 | g | 55.35 | d | 49.77 | r | 41.36 | i | 30.40 | p | 38.87 | ||
| 2000 | 30.38 | k | 37.29 | l | 40.06 | n | 49.17 | l | 53.54 | c | 63.00 | m | 64.15 | r | 68.04 | q | 53.23 | q | 42.38 | w | 27.53 | m | 27.91 | h | 53.54 | |
| 2001 | 24.25 | o | 25.55 | q | 41.31 | m | 47.28 | n | 57.06 | n | 58.98 | e | 66.17 | e | 68.00 | g | 58.00 | s | 49.75 | y | 38.39 | l | 29.50 | m | 62.58 | |
| 2002 | 30.96 | r | 30.05 | q | 33.75 | k | 42.62 | v | 52.61 | m | 57.88 | v | 72.46 | h | 61.27 | r | 62.90 | y | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 2003 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 57.83 | x | 73.40 | j | 67.80 | k | 58.50 | k | 50.83 | k | 31.21 | p | 32.18 | q | 9999.00 | |
| 2004 | 23.14 | t | 28.32 | l | 43.79 | q | 45.94 | m | 52.71 | q | 62.37 | o | 68.96 | s | 70.31 | w | 56.59 | m | 46.09 | o | 36.11 | p | 31.91 | n | 9999.00 | |
| 2005 | 28.17 | s | 29.04 | n | 39.50 | m | 46.31 | v | 50.73 | p | 57.29 | r | 70.33 | p | ----- | z | 58.29 | r | 46.92 | r | 33.97 | n | 17.82 | t | 9999.00 | |
| 2006 | 31.50 | q | 30.36 | n | 36.29 | n | 42.25 | r | 53.85 | n | 63.75 | r | 70.85 | u | 62.76 | l | ----- | z | 43.83 | m | 37.67 | o | 27.68 | q | 9999.00 | |
| 2007 | 25.59 | n | 33.38 | l | 41.16 | l | 43.07 | w | 53.77 | r | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 2008 | 22.90 | 31.67 | 35.58 | 39.58 | 53.44 | 58.53 | 68.12 | o | 66.68 | 57.52 | 47.55 | 38.62 | 26.55 | 43.51 | ||||||||||||
| 2009 | 29.77 | 34.33 | s | 37.69 | g | 42.60 | 54.95 | 58.77 | 68.94 | 65.42 | 61.55 | 42.94 | 33.92 | 22.52 | 48.14 | |||||||||||
| 2010 | 33.58 | 33.23 | 37.24 | 42.18 | 46.32 | 57.60 | 65.81 | 63.65 | 57.62 | 49.15 | 33.90 | 29.39 | 45.81 | |||||||||||||
| 2011 | 27.16 | 29.03 | j | 37.66 | 40.32 | 48.24 | 56.88 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 42.05 | ||||||
| 2012 | 30.50 | z | 32.16 | 38.79 | 46.05 | 51.44 | 57.05 | 68.66 | 67.37 | 59.50 | 45.87 | 36.55 | 28.29 | 48.34 | ||||||||||||
| 2013 | 17.79 | 30.43 | 39.50 | 47.50 | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 29.24 | ||||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 27.79 | 33.42 | 38.24 | 44.19 | 52.41 | 59.57 | 66.89 | 65.18 | 57.07 | 46.55 | 35.80 | 27.54 | 46.54 | |||||||||||||
| S.D. | 4.88 | 3.97 | 2.63 | 3.10 | 2.73 | 2.26 | 2.87 | 2.36 | 3.20 | 2.25 | 3.86 | 4.53 | 1.24 | |||||||||||||
| SKEW | -0.67 | -0.35 | 0.00 | 0.16 | -0.06 | 0.53 | -0.81 | 0.20 | -0.25 | -0.07 | -1.46 | -1.59 | -1.62 | |||||||||||||
| MAX | 35.79 | 41.32 | 43.72 | 51.37 | 58.24 | 65.76 | 71.35 | 70.12 | 62.40 | 51.31 | 42.87 | 33.45 | 48.19 | |||||||||||||
| MIN | 17.39 | 22.30 | 32.20 | 37.65 | 46.32 | 55.03 | 57.40 | 60.84 | 50.05 | 41.66 | 21.74 | 10.08 | 42.76 | |||||||||||||
| NO YRS | 40 | 36 | 40 | 41 | 39 | 37 | 39 | 36 | 37 | 33 | 36 | 36 | 21 | |||||||||||||