| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1983 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 65.03 | 67.87 | 70.52 | 69.77 | 64.03 | 57.93 | 48.84 | 63.43 | ||||||||
| 1984 | 54.29 | 56.17 | 57.74 | 55.67 | 61.03 | 63.03 | 67.74 | 69.26 | 69.37 | 60.58 | 55.87 | 48.94 | 59.97 | |||||||||||||
| 1985 | 51.52 | 52.61 | 52.65 | 57.33 | 61.39 | 66.27 | 69.10 | 67.10 | 65.47 | 63.42 | 49.13 | 52.19 | 59.01 | |||||||||||||
| 1986 | 55.94 | 54.29 | 59.84 | 57.00 | 60.42 | 66.13 | 67.16 | 66.81 | 65.30 | 62.39 | 58.23 | 53.97 | 60.62 | |||||||||||||
| 1987 | 52.94 | 56.14 | 57.19 | 61.24 | a | 62.97 | b | 65.57 | 65.58 | 69.00 | 67.57 | 67.35 | 58.27 | 49.48 | 61.11 | |||||||||||
| 1988 | 51.48 | 55.10 | 56.00 | 57.67 | 60.45 | 64.10 | 69.71 | 68.61 | 69.43 | 65.29 | 56.40 | 52.65 | 60.57 | |||||||||||||
| 1989 | 50.32 | 47.11 | 53.74 | 61.60 | 61.03 | 65.87 | 67.29 | 68.94 | 71.40 | 64.03 | 58.47 | 53.68 | 60.29 | |||||||||||||
| 1990 | 53.00 | 52.21 | 56.65 | 59.20 | 61.61 | 64.77 | 70.26 | 70.55 | 71.00 | 63.39 | 56.77 | 45.94 | 60.44 | |||||||||||||
| 1991 | 52.19 | 59.86 | 54.29 | 55.53 | 57.71 | 62.40 | 70.23 | 68.13 | 73.07 | 67.81 | 58.23 | 52.13 | 60.96 | |||||||||||||
| 1992 | 54.61 | 60.28 | 61.03 | 62.43 | 67.32 | 67.43 | 69.55 | 71.03 | 68.23 | 65.65 | 56.20 | 50.55 | 62.86 | |||||||||||||
| 1993 | 48.03 | 53.25 | 57.29 | 58.57 | 64.13 | 66.20 | 67.58 | 70.39 | 67.50 | 64.45 | 54.40 | 51.42 | 60.27 | |||||||||||||
| 1994 | 55.19 | 52.21 | 59.06 | 58.63 | 63.03 | 64.40 | 68.42 | 71.58 | 70.03 | 63.81 | 52.13 | 52.42 | 60.91 | |||||||||||||
| 1995 | 53.65 | 57.46 | 56.61 | 58.07 | 61.45 | 66.47 | 70.48 | 70.23 | 72.24 | i | 66.00 | i | 60.20 | 54.95 | j | 61.62 | ||||||||||
| 1996 | 53.26 | 55.43 | a | 58.00 | j | 59.87 | 60.68 | 66.25 | j | 70.06 | 70.05 | i | 69.43 | i | 64.35 | 58.33 | i | 54.59 | i | 60.61 | ||||||
| 1997 | 52.94 | 54.86 | 56.32 | 59.03 | 66.77 | 66.52 | i | 71.48 | 73.86 | j | 71.60 | 63.68 | 58.60 | j | 53.10 | 61.09 | ||||||||||
| 1998 | 53.81 | 54.74 | a | 56.73 | i | 57.00 | 59.60 | k | 63.10 | i | ----- | z | 71.90 | j | 69.90 | 64.81 | 56.81 | i | 50.68 | 58.49 | ||||||
| 1999 | 51.91 | i | 51.32 | 53.29 | 56.97 | 58.58 | 63.87 | 66.45 | 68.35 | 68.87 | 64.58 | 58.30 | 53.35 | 60.36 | ||||||||||||
| 2000 | 52.19 | 53.69 | 55.06 | 60.95 | k | 61.81 | 64.86 | a | 68.62 | j | 69.61 | 71.90 | i | 64.05 | i | 55.30 | j | 54.81 | j | 59.54 | ||||||
| 2001 | 53.90 | a | 54.14 | 56.73 | i | 56.24 | i | 64.61 | 64.62 | i | 67.58 | l | 68.32 | 68.37 | k | 65.29 | 60.10 | j | 52.57 | j | 61.25 | |||||
| 2002 | 52.04 | h | 56.65 | h | 55.38 | j | 58.45 | h | 59.87 | h | 67.65 | j | 70.52 | j | 72.73 | i | 71.76 | i | 63.61 | h | 61.11 | k | 55.77 | i | 9999.00 | |
| 2003 | 58.83 | h | 56.00 | h | ----- | z | 57.95 | i | 64.95 | j | 70.24 | i | 71.83 | h | 72.48 | j | 72.38 | i | 66.65 | h | 53.94 | l | 54.15 | k | 9999.00 | |
| 2004 | 53.67 | j | 56.50 | i | 60.48 | h | 63.86 | h | 62.95 | k | 66.68 | h | 71.91 | i | 72.73 | i | 69.35 | j | 64.29 | j | 57.15 | j | 54.75 | k | 9999.00 | |
| 2005 | 54.14 | j | 61.15 | h | 59.87 | h | 59.19 | i | 64.38 | j | 65.77 | h | 72.42 | l | 70.43 | h | 69.29 | i | 64.05 | l | 57.50 | j | 54.19 | j | 9999.00 | |
| 2006 | 55.10 | j | 55.00 | h | 53.87 | h | 59.74 | k | 65.95 | i | 67.14 | h | 70.48 | j | 68.39 | h | 71.70 | j | 65.86 | i | 56.14 | i | 54.65 | k | 9999.00 | |
| 2007 | 51.29 | n | 53.45 | h | 56.73 | i | 59.24 | i | 62.82 | i | 65.23 | h | 70.19 | j | 72.00 | h | 68.05 | i | 63.61 | h | 58.05 | j | 52.00 | l | 9999.00 | |
| 2008 | 49.29 | j | 53.67 | h | 54.10 | j | 55.50 | h | 62.41 | i | 62.52 | i | 68.22 | h | 69.05 | j | 69.18 | h | 63.48 | j | 58.75 | j | 50.43 | h | 9999.00 | |
| 2009 | 54.68 | i | 55.10 | h | 53.73 | i | 57.36 | h | 62.30 | k | 65.18 | h | 70.22 | h | 70.81 | j | 72.76 | i | 63.68 | i | 58.71 | i | 49.77 | i | 9999.00 | |
| 2010 | 56.15 | k | 56.74 | i | 57.17 | h | 56.91 | h | 59.29 | j | 63.50 | h | 66.61 | h | 69.77 | i | 70.14 | h | 66.52 | j | 55.71 | i | 53.91 | h | 9999.00 | |
| 2011 | 54.05 | j | 52.55 | h | 54.39 | h | 55.05 | i | 59.55 | i | 65.05 | h | 68.80 | k | 71.96 | h | 72.50 | h | 64.76 | j | 56.09 | h | 52.91 | i | 9999.00 | |
| 2012 | 54.32 | i | 54.05 | h | 52.64 | i | 57.90 | i | 61.13 | h | 65.29 | i | 67.50 | i | 70.04 | h | 68.00 | j | 64.30 | h | 58.57 | i | 51.82 | n | 9999.00 | |
| 2013 | 51.48 | j | 52.72 | j | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 52.90 | 54.49 | 56.45 | 58.49 | 62.06 | 65.09 | 68.69 | 69.28 | 69.23 | 64.41 | 56.47 | 51.29 | 60.64 | |||||||||||||
| S.D. | 1.89 | 3.06 | 2.40 | 2.02 | 2.55 | 1.38 | 1.66 | 1.37 | 2.17 | 1.69 | 2.91 | 2.23 | 0.93 | |||||||||||||
| SKEW | -0.85 | -0.17 | 0.19 | 0.46 | 0.54 | -0.27 | -0.18 | -0.13 | -0.28 | 0.03 | -1.29 | -0.89 | 0.84 | |||||||||||||
| MAX | 55.94 | 60.28 | 61.03 | 62.43 | 67.32 | 67.43 | 71.48 | 71.58 | 73.07 | 67.81 | 60.20 | 53.97 | 62.86 | |||||||||||||
| MIN | 48.03 | 47.11 | 52.65 | 55.53 | 57.71 | 62.40 | 65.58 | 66.81 | 65.30 | 60.58 | 49.13 | 45.94 | 59.01 | |||||||||||||
| NO YRS | 17 | 18 | 15 | 16 | 17 | 15 | 16 | 16 | 15 | 17 | 14 | 15 | 11 | |||||||||||||