| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1978 | ----- | z | ----- | z | ----- | z | 64.07 | c | 75.40 | a | 89.07 | a | 97.74 | 95.68 | 81.75 | b | 77.06 | 50.07 | 39.93 | b | 74.53 | c | ||||
| 1979 | 31.16 | 34.46 | 55.66 | b | 67.60 | 78.79 | c | 90.93 | 97.90 | 91.10 | 91.80 | 75.00 | 51.86 | a | 47.55 | i | 69.66 | a | ||||||||
| 1980 | 47.03 | 54.10 | 54.97 | a | 69.37 | 72.00 | 89.37 | 99.90 | 96.97 | 85.86 | b | 73.07 | a | 56.60 | 50.17 | a | 70.78 | |||||||||
| 1981 | 49.94 | 49.21 | 58.13 | 73.30 | 77.63 | d | 95.00 | 102.10 | 101.36 | c | 90.40 | 65.63 | a | 58.74 | c | 47.83 | b | 72.44 | ||||||||
| 1982 | 41.39 | c | 55.35 | e | 57.23 | a | 67.45 | a | 79.50 | a | 89.10 | a | 97.00 | a | 96.86 | b | 80.86 | b | 64.90 | b | 50.41 | c | 43.63 | a | 68.64 | |
| 1983 | 42.48 | 48.18 | 55.43 | a | 60.22 | c | 79.84 | f | 89.26 | c | 96.23 | 90.74 | 87.00 | a | 71.69 | b | 52.50 | f | 44.45 | b | 68.57 | b | ||||
| 1984 | 44.04 | d | 52.83 | f | 59.97 | 68.46 | b | 87.00 | a | 89.73 | 96.83 | a | 92.36 | c | 85.10 | a | 64.38 | b | 53.15 | c | 34.46 | e | 70.50 | a | ||
| 1985 | 27.80 | a | 34.71 | 57.47 | a | 75.96 | c | 83.16 | 97.53 | 100.86 | b | 96.20 | a | 79.65 | g | 70.44 | d | 41.78 | g | 42.76 | b | 68.69 | b | |||
| 1986 | 47.30 | d | 54.57 | 64.44 | f | 68.08 | d | 79.76 | b | 92.33 | c | 91.79 | c | 93.89 | c | 77.31 | a | 67.35 | e | 56.52 | c | 43.78 | d | 70.24 | a | |
| 1987 | 31.73 | e | 47.93 | a | 56.26 | h | 73.20 | e | 76.36 | c | 89.04 | b | 91.47 | a | 93.52 | 84.42 | d | 73.50 | a | 51.23 | d | 38.45 | b | 68.26 | a | |
| 1988 | 27.04 | e | 38.34 | 58.26 | d | 66.74 | c | 75.04 | c | 87.21 | a | 96.45 | 90.63 | a | 81.86 | a | 76.87 | 54.22 | c | 40.08 | e | 66.06 | ||||
| 1989 | 23.46 | c | 41.25 | d | 64.22 | d | 74.13 | 75.68 | c | 84.97 | 95.73 | a | 88.29 | 82.90 | 68.89 | d | 55.36 | b | 46.13 | a | 66.75 | |||||
| 1990 | 43.73 | e | 45.42 | d | 61.24 | b | 70.83 | a | 75.34 | b | 87.50 | 94.29 | 90.42 | 84.66 | a | 74.23 | e | 53.48 | c | 39.76 | b | 68.41 | ||||
| 1991 | 39.07 | c | 57.21 | 52.28 | b | 63.70 | c | 70.52 | d | 83.17 | 93.74 | 90.70 | a | 81.73 | 73.14 | b | 52.43 | 40.34 | b | 66.50 | ||||||
| 1992 | 34.44 | d | 52.86 | 58.10 | b | 74.00 | 81.62 | b | 84.28 | a | 89.90 | 92.52 | 84.48 | a | 72.97 | b | 47.83 | a | 36.00 | b | 67.42 | |||||
| 1993 | 32.18 | c | 41.43 | 60.33 | a | 66.93 | a | 79.07 | a | 81.53 | 91.40 | a | 90.00 | 83.90 | a | 67.10 | b | 49.25 | b | 39.27 | e | 65.20 | ||||
| 1994 | 43.42 | 45.96 | b | 63.20 | a | 66.00 | a | 76.71 | 91.63 | 96.26 | 93.67 | a | 82.93 | 66.53 | a | 43.81 | c | 36.17 | b | 67.19 | ||||||
| 1995 | 42.00 | b | 57.48 | a | 55.55 | b | 63.75 | b | 67.54 | c | 79.25 | b | 92.33 | d | 92.55 | 86.29 | b | 72.45 | b | 60.24 | a | 46.13 | 67.96 | |||
| 1996 | 46.21 | b | 54.48 | b | 60.40 | a | 69.69 | a | 76.48 | 91.03 | a | 96.77 | 94.48 | 82.31 | a | 68.38 | b | 52.41 | c | 43.59 | d | 69.69 | ||||
| 1997 | 38.59 | d | 47.92 | c | 64.32 | 64.29 | b | 81.13 | 84.97 | a | 90.55 | 91.84 | 80.67 | 70.32 | c | 53.83 | a | 38.77 | a | 67.27 | ||||||
| 1998 | 45.50 | a | 43.70 | a | 57.32 | c | 60.90 | 69.72 | b | 79.29 | b | 92.61 | 92.97 | 78.86 | b | 64.37 | d | 52.18 | b | 42.00 | 64.95 | |||||
| 1999 | 45.90 | b | 46.79 | 61.37 | a | 58.69 | a | 73.71 | 83.87 | 90.88 | g | 88.97 | 81.62 | a | 74.17 | a | ----- | z | 44.61 | 65.97 | b | |||||
| 2000 | 49.40 | f | 51.00 | a | 57.97 | b | 70.57 | b | 78.87 | 88.14 | a | 93.10 | 90.77 | 82.24 | a | 67.52 | 45.30 | 45.03 | 70.05 | a | ||||||
| 2001 | 39.00 | a | 44.29 | 59.19 | 63.20 | 81.58 | 87.93 | 90.55 | 94.00 | 85.37 | 74.67 | a | 55.57 | 35.84 | 67.60 | |||||||||||
| 2002 | 39.57 | a | 47.61 | 54.73 | a | 70.97 | 75.40 | a | 88.53 | 96.06 | 91.23 | 82.63 | 67.55 | 53.97 | a | 44.23 | a | 67.71 | ||||||||
| 2003 | 52.03 | a | 48.25 | 59.19 | 61.93 | b | 76.41 | b | 87.69 | a | 96.03 | 89.55 | 83.23 | 78.07 | a | 48.23 | 41.15 | d | 68.48 | |||||||
| 2004 | 29.27 | e | 40.90 | 66.71 | 67.24 | a | 76.97 | a | 87.68 | b | 92.03 | 88.03 | a | 81.30 | 65.77 | 49.97 | a | 42.52 | 65.70 | |||||||
| 2005 | 44.06 | 49.61 | 56.47 | a | 62.77 | 74.42 | 81.76 | a | 96.20 | a | 89.26 | 78.45 | j | 70.23 | 56.28 | a | 42.35 | 65.76 | a | |||||||
| 2006 | 45.33 | a | 50.64 | 51.52 | 65.47 | 78.65 | 88.96 | c | 93.32 | 89.68 | 79.67 | 67.29 | 54.76 | a | 37.10 | a | 66.87 | |||||||||
| 2007 | 31.65 | 49.80 | h | 61.90 | 68.09 | g | 78.30 | d | 88.00 | 95.97 | 91.26 | 79.97 | 67.32 | 57.47 | 37.65 | 68.95 | b | |||||||||
| 2008 | 38.65 | 48.28 | 58.61 | 65.10 | 73.03 | 87.10 | j | 95.11 | c | 94.94 | 84.10 | 70.77 | 56.37 | 39.06 | 65.82 | a | ||||||||||
| 2009 | 36.16 | 44.64 | 56.71 | 63.66 | a | 80.50 | e | 78.70 | 93.23 | 89.52 | 86.93 | 64.32 | 54.73 | 31.94 | 65.09 | |||||||||||
| 2010 | 28.73 | a | 40.86 | 54.55 | 61.57 | 67.62 | g | 85.93 | c | 94.47 | a | 91.29 | c | 85.93 | 68.06 | 50.37 | 43.72 | b | 64.13 | a | ||||||
| 2011 | 41.13 | 48.15 | a | 56.81 | 62.41 | a | 69.55 | b | 82.87 | 92.47 | a | 93.53 | a | 85.12 | e | 70.19 | 49.82 | b | 42.16 | 66.18 | ||||||
| 2012 | 44.81 | 47.97 | 60.00 | 68.43 | 78.61 | 89.67 | 93.10 | 93.23 | 84.79 | a | 71.43 | c | 60.41 | h | 33.64 | i | 73.20 | b | ||||||||
| 2013 | 25.13 | a | 44.32 | 61.03 | b | 67.17 | 75.77 | 91.00 | b | 95.16 | 91.39 | 78.97 | a | 66.52 | 54.60 | 29.35 | 65.03 | |||||||||
| 2014 | 38.29 | 51.11 | 59.45 | 66.53 | 75.65 | 88.00 | 95.23 | 87.55 | 85.23 | 74.90 | 60.36 | h | 47.23 | 69.92 | a | |||||||||||
| 2015 | 49.03 | 59.07 | 65.32 | 67.20 | 72.26 | 92.00 | 90.65 | 93.10 | 86.53 | 71.77 | 48.90 | 39.35 | 69.60 | |||||||||||||
| 2016 | 33.77 | 33.86 | 61.13 | 67.17 | 73.23 | 92.17 | 96.29 | 93.32 | 83.60 | 72.29 | 59.97 | 41.68 | 67.37 | |||||||||||||
| 2017 | 39.90 | 51.96 | 63.65 | 65.40 | 77.74 | 92.43 | 96.81 | 93.87 | 81.97 | 70.81 | 59.57 | 46.23 | 70.03 | |||||||||||||
| 2018 | 46.90 | 49.11 | 54.52 | 70.47 | 77.90 | a | 91.60 | 96.58 | 94.94 | 86.90 | 67.14 | i | 46.20 | y | 42.39 | 71.13 | b | |||||||||
| 2019 | 44.00 | a | 42.07 | 55.23 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 47.10 | i | ||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 39.30 | 47.31 | 58.72 | 66.87 | 76.59 | 87.83 | 94.86 | 92.34 | 83.62 | 70.30 | 53.13 | 41.21 | 67.56 | |||||||||||||
| S.D. | 7.38 | 6.23 | 3.55 | 4.09 | 3.94 | 4.24 | 2.85 | 2.78 | 3.01 | 3.78 | 3.98 | 4.37 | 1.90 | |||||||||||||
| SKEW | -0.46 | -0.31 | 0.22 | 0.24 | -0.00 | -0.35 | 0.32 | 0.76 | 0.38 | 0.16 | -0.21 | -0.50 | 0.68 | |||||||||||||
| MAX | 52.03 | 59.07 | 66.71 | 75.96 | 87.00 | 97.53 | 102.10 | 101.36 | 91.80 | 78.07 | 60.24 | 50.17 | 72.44 | |||||||||||||
| MIN | 23.46 | 33.86 | 51.52 | 58.69 | 67.54 | 78.70 | 89.90 | 87.55 | 77.31 | 64.32 | 43.81 | 29.35 | 64.95 | |||||||||||||
| YRS | 40 | 39 | 39 | 40 | 39 | 40 | 40 | 41 | 39 | 40 | 35 | 39 | 25 | |||||||||||||