| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1974 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 90.26 | 86.69 | a | 69.55 | 56.48 | a | 45.77 | a | 69.75 | g | ||
| 1975 | 46.63 | a | 49.29 | 54.42 | 55.53 | 72.55 | 81.47 | 93.13 | 87.16 | 84.87 | 67.68 | 55.50 | b | 50.43 | a | 66.55 | ||||||||||
| 1976 | 49.52 | 52.21 | a | 57.29 | 62.27 | 78.77 | 81.33 | 90.77 | 82.00 | 80.23 | 70.00 | 61.87 | 49.45 | 67.98 | ||||||||||||
| 1977 | 46.23 | a | 57.29 | 53.55 | 70.20 | 64.13 | 86.30 | 91.87 | a | 90.90 | 80.97 | 73.43 | a | 59.34 | a | 51.61 | 68.82 | |||||||||
| 1978 | 48.45 | 51.82 | 61.30 | a | 61.29 | b | 71.58 | 81.97 | 91.19 | 88.97 | 76.59 | a | 75.45 | 50.00 | a | 40.31 | b | 66.58 | ||||||||
| 1979 | 40.41 | b | 50.54 | 59.77 | a | 68.33 | f | 78.13 | 85.07 | b | 91.72 | b | 86.97 | b | 85.07 | 71.66 | b | 53.37 | 51.26 | 68.54 | a | |||||
| 1980 | 46.76 | f | 53.62 | 56.36 | f | 67.17 | 70.20 | f | 82.80 | j | 90.70 | a | 84.40 | a | 77.60 | 66.16 | 54.12 | d | 49.32 | i | 70.54 | e | ||||
| 1981 | 45.68 | c | 56.15 | a | 57.57 | a | 67.37 | 75.16 | 82.31 | d | ----- | z | 81.71 | 84.23 | 68.74 | 60.86 | a | 57.58 | 67.03 | a | ||||||
| 1982 | 41.52 | b | 57.25 | 56.27 | a | 64.87 | 77.13 | 85.20 | 90.03 | 91.17 | g | 75.57 | g | 66.68 | 50.75 | b | 46.03 | 63.57 | b | |||||||
| 1983 | 47.20 | a | 52.75 | 54.39 | 58.27 | 73.61 | 82.23 | 87.10 | 88.03 | a | 81.19 | d | 68.62 | g | 52.53 | m | 44.77 | 66.95 | b | |||||||
| 1984 | 39.10 | a | 49.34 | 59.86 | b | 61.10 | a | 77.21 | b | 80.58 | d | 94.68 | 92.00 | b | 82.69 | a | 59.50 | g | 51.87 | 42.45 | 66.44 | a | ||||
| 1985 | 38.90 | a | 47.73 | b | 51.13 | 70.13 | 75.29 | 88.34 | a | 94.60 | f | 89.77 | a | 74.52 | a | 66.50 | g | 45.42 | f | 39.61 | 63.94 | c | ||||
| 1986 | 50.60 | a | 53.89 | 63.39 | 66.11 | c | 74.77 | 88.77 | 90.60 | k | 94.33 | a | 74.00 | a | 70.06 | m | 60.83 | f | 48.58 | 68.27 | c | |||||
| 1987 | 42.57 | a | 51.14 | 57.33 | d | 69.62 | a | 75.67 | g | 84.41 | c | 86.93 | b | 90.97 | 84.46 | d | 73.86 | b | 52.93 | b | 41.83 | a | 66.91 | a | ||
| 1988 | 42.21 | c | 54.21 | 60.30 | d | 66.42 | d | 73.54 | c | 88.48 | c | 98.29 | q | 92.75 | c | 84.11 | b | 79.14 | c | 55.11 | b | 43.27 | a | 67.23 | a | |
| 1989 | 41.00 | d | 39.20 | c | 59.88 | f | 72.37 | c | 72.07 | b | 86.11 | c | 94.59 | d | 86.11 | c | 80.79 | a | 69.15 | e | 57.82 | b | 50.63 | a | 68.17 | a |
| 1990 | 45.12 | g | 44.71 | 61.77 | 69.29 | i | 70.07 | a | 85.68 | b | 92.63 | d | 90.00 | a | 84.48 | e | 72.52 | 56.07 | 36.10 | a | 69.40 | b | ||||
| 1991 | 41.79 | c | 58.75 | 51.29 | c | 62.96 | c | 67.28 | b | 80.17 | 93.74 | 90.62 | g | 85.10 | 74.13 | 56.50 | b | 46.83 | a | 65.32 | a | |||||
| 1992 | 46.10 | 55.59 | b | 62.10 | a | 73.33 | f | 81.53 | a | 82.22 | c | 89.84 | 91.73 | a | 84.00 | a | 71.65 | 53.46 | b | 43.20 | a | 69.22 | a | |||
| 1993 | 35.71 | 45.64 | c | 63.45 | 65.00 | e | 76.42 | 78.57 | 87.03 | a | 88.17 | a | 83.67 | 68.59 | d | 51.13 | 45.06 | 65.70 | ||||||||
| 1994 | 49.87 | 50.58 | b | 63.97 | a | 69.36 | e | 75.06 | 87.57 | b | 95.23 | 93.52 | 83.38 | d | 67.31 | b | 43.69 | a | 42.69 | b | 68.52 | |||||
| 1995 | 46.03 | a | 60.86 | 56.58 | 64.19 | d | 66.96 | d | 78.83 | a | 89.65 | 91.58 | 85.53 | 72.20 | a | 65.07 | 50.16 | 68.97 | ||||||||
| 1996 | 49.84 | 53.72 | 60.19 | 67.47 | 74.37 | d | 84.70 | 95.52 | 93.42 | 80.53 | 68.19 | 56.93 | a | 50.24 | b | 69.59 | ||||||||||
| 1997 | 45.50 | a | 51.32 | 65.33 | d | 65.12 | e | 80.45 | b | 80.00 | 89.87 | 92.42 | 82.30 | 68.15 | d | 57.45 | a | 42.42 | 68.36 | |||||||
| 1998 | 51.71 | 47.96 | a | 57.52 | 62.43 | b | 65.10 | a | 77.77 | 93.68 | 94.77 | 79.70 | 64.83 | b | 53.40 | e | 42.83 | a | 65.97 | |||||||
| 1999 | 50.07 | d | 53.59 | a | 59.38 | b | 62.46 | d | 74.18 | c | 83.10 | 91.65 | 88.45 | b | 83.40 | 74.55 | i | 63.30 | 49.19 | 68.98 | a | |||||
| 2000 | 49.61 | 53.37 | b | 59.84 | 70.70 | 75.97 | 88.20 | 96.45 | ----- | z | 81.48 | a | 69.90 | 50.33 | c | 50.95 | i | 69.59 | b | |||||||
| 2001 | 41.71 | x | 47.64 | 63.55 | 65.10 | a | 81.93 | c | ----- | z | 93.58 | s | ----- | z | ----- | z | 75.38 | b | 60.13 | 45.87 | a | 62.80 | e | |||
| 2002 | 47.14 | c | 55.24 | c | 57.79 | c | 69.14 | h | 71.76 | f | 83.96 | f | 97.48 | 90.66 | b | 81.77 | 67.97 | 57.08 | e | 46.67 | a | 66.87 | c | |||
| 2003 | 56.06 | 49.61 | e | 61.34 | b | 59.08 | f | 75.57 | c | 86.53 | 98.03 | 90.59 | b | ----- | z | ----- | z | ----- | z | ----- | z | 73.96 | e | |||
| 2004 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 2005 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 2006 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 2007 | 42.18 | i | 52.78 | e | 64.90 | 67.37 | ----- | z | 87.77 | d | 98.62 | g | 95.19 | 80.87 | 67.52 | 61.83 | g | ----- | z | 73.77 | e | |||||
| 2008 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 74.90 | t | ----- | z | ----- | z | 85.83 | 71.93 | b | 59.00 | a | 44.58 | 65.34 | h | ||
| 2009 | 48.50 | c | 51.68 | 56.35 | 63.83 | 80.87 | 80.53 | 96.71 | 92.03 | 89.97 | a | 65.00 | ----- | z | ----- | z | 72.55 | b | ||||||||
| 2010 | ----- | z | ----- | z | ----- | z | ----- | z | 64.65 | 81.30 | 92.29 | j | 91.00 | m | ----- | z | ----- | z | ----- | z | ----- | z | 72.97 | j | ||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 45.85 | 51.92 | 59.03 | 65.33 | 74.08 | 83.64 | 92.41 | 89.96 | 82.33 | 70.25 | 55.69 | 46.05 | 67.70 | |||||||||||||
| S.D. | 4.67 | 4.38 | 3.86 | 3.97 | 4.99 | 3.32 | 3.20 | 3.49 | 3.49 | 3.49 | 4.63 | 4.53 | 1.38 | |||||||||||||
| SKEW | -0.18 | -0.57 | -0.30 | -0.41 | -0.49 | 0.01 | -0.02 | -0.77 | -0.57 | 0.58 | -0.22 | 0.21 | -0.23 | |||||||||||||
| MAX | 56.06 | 60.86 | 65.33 | 72.37 | 81.93 | 88.77 | 98.03 | 95.19 | 89.97 | 79.14 | 65.07 | 57.58 | 69.59 | |||||||||||||
| MIN | 35.71 | 39.20 | 51.13 | 55.53 | 64.13 | 77.77 | 86.93 | 81.71 | 74.00 | 64.83 | 43.69 | 36.10 | 65.70 | |||||||||||||
| YRS | 27 | 31 | 29 | 26 | 28 | 29 | 25 | 28 | 30 | 27 | 27 | 28 | 10 | |||||||||||||