| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1978 | ----- | z | ----- | z | ----- | z | 49.76 | e | 58.07 | d | 69.59 | a | 75.97 | 73.90 | 61.93 | b | 56.71 | 38.38 | 26.72 | b | 56.78 | c | ||||
| 1979 | 20.19 | 22.32 | 42.34 | b | 51.00 | 59.82 | c | 68.77 | 75.58 | 72.35 | 70.02 | 56.79 | 37.47 | a | 33.20 | i | 52.42 | a | ||||||||
| 1980 | 35.80 | a | 41.03 | 41.23 | a | 52.20 | 56.60 | a | 68.75 | 78.45 | 75.16 | 65.73 | b | 54.07 | a | 40.93 | 34.81 | b | 53.73 | |||||||
| 1981 | 35.15 | 33.80 | 43.50 | 55.90 | 60.98 | d | 75.40 | 78.76 | 78.09 | c | 69.40 | 50.70 | a | 43.59 | c | 35.02 | b | 55.02 | ||||||||
| 1982 | 28.11 | c | 39.55 | f | 42.98 | b | 49.71 | b | 61.59 | b | 69.71 | a | 76.17 | a | 76.14 | b | 64.75 | d | 49.36 | b | 38.67 | c | 33.43 | a | 53.69 | a |
| 1983 | 31.00 | d | 37.91 | a | 44.32 | a | 46.67 | c | 61.00 | f | 69.85 | d | 76.08 | 74.08 | 68.27 | b | 54.71 | b | 38.87 | g | 34.91 | c | 53.78 | b | ||
| 1984 | 32.07 | d | 37.15 | f | 43.48 | a | 49.83 | d | 66.95 | b | 69.95 | 78.70 | a | 74.73 | c | 67.07 | a | 48.27 | c | 38.60 | d | 24.22 | f | 56.96 | b | |
| 1985 | 13.79 | c | 19.68 | 43.54 | e | 56.65 | c | 63.84 | 75.85 | 79.79 | b | 74.43 | a | 62.91 | g | 53.10 | e | 29.89 | h | 31.59 | b | 51.22 | b | |||
| 1986 | 35.96 | e | 42.57 | a | 48.81 | g | 52.29 | d | 61.60 | b | 73.30 | c | 73.00 | c | 75.69 | d | 61.14 | b | 51.04 | e | 40.61 | c | 29.67 | d | 54.26 | a |
| 1987 | 20.83 | e | 35.74 | a | 42.00 | h | 53.95 | h | 61.08 | e | 71.34 | b | 73.17 | a | 74.10 | a | 66.54 | d | 56.37 | a | 40.04 | f | 28.21 | c | 54.15 | c |
| 1988 | 15.29 | g | 24.16 | 42.75 | e | 51.19 | d | 58.35 | d | 70.15 | c | 77.52 | 73.48 | b | 63.93 | a | 58.34 | 40.87 | d | 26.90 | e | 53.42 | a | |||
| 1989 | 10.36 | c | 28.27 | f | 48.74 | d | 56.84 | a | 59.88 | c | 67.73 | 76.77 | a | 70.10 | 64.33 | a | 51.50 | e | 38.46 | b | 29.63 | a | 52.21 | a | ||
| 1990 | 29.60 | f | 32.00 | e | 46.41 | b | 54.13 | c | 59.03 | b | 69.52 | 77.27 | 72.98 | 67.11 | b | 55.27 | e | 38.15 | c | 24.80 | c | 54.24 | a | |||
| 1991 | 26.86 | c | 39.78 | a | 39.64 | b | 47.76 | c | 55.94 | d | 67.58 | 76.63 | 73.37 | a | 64.68 | b | 55.59 | b | 39.14 | a | 27.36 | b | 51.19 | |||
| 1992 | 22.46 | g | 40.86 | 46.39 | c | 56.27 | 64.72 | b | 67.64 | a | 73.92 | a | 75.06 | 65.83 | a | 56.55 | b | 34.09 | a | 25.00 | b | 55.12 | a | |||
| 1993 | 25.16 | f | 33.29 | 47.29 | b | 51.78 | a | 63.00 | a | 65.38 | a | 72.93 | a | 72.48 | a | 64.43 | a | 51.86 | b | 35.18 | b | 26.40 | e | 53.09 | a | |
| 1994 | 30.28 | a | 33.98 | b | 47.30 | a | 51.05 | a | 60.73 | a | 72.42 | 77.79 | 75.03 | a | 64.33 | 51.18 | a | 31.52 | e | 26.54 | c | 51.85 | ||||
| 1995 | 34.76 | b | 43.29 | b | 42.93 | d | 48.67 | c | 54.93 | c | 63.52 | d | 74.37 | d | 74.19 | 67.20 | b | 53.72 | b | 43.07 | a | 33.00 | 52.80 | |||
| 1996 | 32.64 | b | 40.35 | b | 44.52 | b | 52.64 | a | 60.95 | a | 72.52 | b | 78.42 | 75.68 | 63.97 | a | 51.26 | b | 39.50 | c | 33.63 | e | 53.84 | |||
| 1997 | 29.78 | d | 37.04 | c | 46.81 | 49.07 | b | 63.34 | 69.60 | a | 73.76 | 73.84 | 66.07 | 52.14 | c | 40.75 | b | 29.13 | a | 52.61 | ||||||
| 1998 | 35.02 | a | 36.13 | a | 43.98 | e | 47.48 | 54.62 | b | 63.87 | c | 75.81 | 75.98 | 65.07 | b | 49.91 | d | 40.21 | b | 29.97 | 51.50 | |||||
| 1999 | 32.79 | b | 35.34 | 45.33 | a | 46.54 | c | 58.63 | 67.38 | 75.48 | g | 72.21 | 64.41 | a | 53.79 | b | ----- | z | 29.47 | a | 50.59 | b | ||||
| 2000 | 36.34 | f | 39.93 | a | 44.41 | b | 54.62 | b | 62.61 | 70.81 | a | 73.98 | 73.65 | 64.22 | a | 52.92 | a | 33.53 | 32.02 | a | 54.79 | a | ||||
| 2001 | 28.47 | a | 33.79 | b | 46.02 | a | 48.85 | 64.18 | 70.38 | 73.03 | 75.52 | a | 67.17 | 56.55 | a | 42.19 | a | 25.77 | c | 52.66 | ||||||
| 2002 | 29.83 | b | 34.52 | 39.63 | a | 54.22 | 58.87 | a | 70.53 | 78.15 | 72.92 | 65.33 | 50.23 | a | 38.36 | a | 31.07 | c | 51.97 | |||||||
| 2003 | 37.18 | a | 35.24 | a | 44.27 | a | 48.65 | c | 60.66 | b | 71.02 | a | 78.16 | 73.87 | a | 66.35 | 58.85 | a | 36.38 | b | 27.90 | j | 55.51 | a | ||
| 2004 | 17.54 | g | 32.00 | a | 50.58 | 53.09 | b | 60.65 | a | 70.98 | b | 74.73 | 71.68 | a | 63.48 | 52.62 | a | 39.20 | c | 31.38 | a | 54.58 | a | |||
| 2005 | 35.03 | 39.74 | a | 43.48 | a | 48.62 | 60.45 | 65.91 | b | 78.28 | b | 73.06 | 61.55 | j | 53.92 | 41.27 | b | 30.58 | 51.85 | a | ||||||
| 2006 | 33.40 | a | 35.02 | a | 38.42 | a | 51.75 | 63.27 | a | 73.06 | c | 77.48 | 71.44 | 63.22 | a | 51.26 | 38.83 | a | 24.92 | a | 51.84 | |||||
| 2007 | 19.32 | a | 36.17 | h | 46.15 | 53.37 | g | 60.81 | d | 70.12 | 78.85 | 74.89 | 64.05 | 51.18 | 41.23 | 27.55 | a | 53.41 | b | |||||||
| 2008 | 28.56 | 35.68 | a | 43.35 | a | 47.05 | k | 51.69 | j | 64.60 | o | 76.77 | c | 75.81 | 65.93 | 52.42 | 43.13 | 26.35 | 49.78 | c | ||||||
| 2009 | 24.60 | 34.14 | 42.56 | 48.84 | a | 64.67 | e | 65.37 | 76.35 | 71.85 | 68.88 | 49.89 | 39.03 | 20.66 | 50.57 | |||||||||||
| 2010 | 18.58 | a | 32.77 | 41.65 | 47.65 | 53.35 | g | 69.81 | c | 77.00 | a | 73.77 | c | 65.42 | 54.63 | 38.30 | 35.48 | b | 50.46 | a | ||||||
| 2011 | 30.32 | 34.63 | a | 43.31 | 48.45 | a | 55.17 | b | 67.33 | a | 74.73 | a | 74.87 | a | 67.04 | e | 53.73 | 36.00 | b | 28.40 | 51.16 | |||||
| 2012 | 30.63 | 35.71 | 45.24 | 52.85 | 61.83 | a | 70.57 | 74.35 | 76.35 | 66.71 | a | 54.54 | c | 44.80 | h | 23.02 | i | 56.88 | b | |||||||
| 2013 | 12.18 | a | 33.75 | 47.22 | b | 51.95 | 60.10 | 73.50 | b | 78.61 | 73.19 | 65.10 | a | 49.73 | 40.62 | 17.11 | 50.26 | |||||||||
| 2014 | 24.66 | 38.71 | 45.15 | 52.00 | 60.26 | 71.17 | 79.06 | 71.84 | 69.15 | 57.44 | 44.34 | h | 35.78 | b | 55.02 | a | ||||||||||
| 2015 | 36.29 | 43.48 | 49.03 | 51.30 | 59.02 | 74.30 | 74.21 | 75.21 | 68.63 | 57.13 | 35.68 | 28.63 | 54.41 | |||||||||||||
| 2016 | 24.47 | 22.50 | 47.50 | 53.33 | 58.97 | 75.30 | 77.45 | 74.32 | 65.07 | 56.06 | 42.93 | 29.39 | 52.27 | |||||||||||||
| 2017 | 29.56 | 40.84 | 48.58 | 51.73 | 62.15 | 74.62 | 79.77 | 76.98 | 65.48 | 52.66 | 44.12 | 30.76 | 54.77 | |||||||||||||
| 2018 | 33.76 | 35.12 | 41.60 | b | 55.42 | 62.60 | a | 73.30 | 80.06 | 77.00 | 68.00 | 54.73 | i | 36.00 | y | 31.58 | 55.84 | b | ||||||||
| 2019 | 33.27 | a | 31.71 | 44.10 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 36.36 | i | ||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 28.44 | 35.10 | 44.51 | 51.34 | 60.55 | 70.20 | 76.55 | 74.18 | 65.78 | 53.45 | 39.12 | 29.29 | 52.50 | |||||||||||||
| S.D. | 7.13 | 5.63 | 2.71 | 2.86 | 2.82 | 3.06 | 2.11 | 1.70 | 2.02 | 2.72 | 2.96 | 4.06 | 1.44 | |||||||||||||
| SKEW | -1.03 | -1.02 | 0.01 | 0.24 | -0.22 | -0.18 | -0.21 | -0.05 | 0.11 | 0.14 | -0.51 | -0.65 | 0.31 | |||||||||||||
| MAX | 37.18 | 43.48 | 50.58 | 56.84 | 66.95 | 75.85 | 80.06 | 78.09 | 70.02 | 58.85 | 44.12 | 35.78 | 55.02 | |||||||||||||
| MIN | 10.36 | 19.68 | 38.42 | 46.54 | 54.62 | 63.52 | 72.93 | 70.10 | 61.14 | 48.27 | 31.52 | 17.11 | 50.26 | |||||||||||||
| YRS | 35 | 37 | 39 | 38 | 38 | 40 | 40 | 41 | 39 | 40 | 34 | 37 | 17 | |||||||||||||