| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1976 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 54.62 | b | 52.03 | 43.48 | 39.00 | 33.87 | 44.60 | |||||
| 1977 | 27.66 | b | 36.89 | 36.52 | 40.17 | 44.03 | 50.70 | 52.35 | 58.00 | 51.37 | 43.45 | 38.00 | 37.87 | 43.08 | ||||||||||||
| 1978 | 37.06 | ----- | z | 40.55 | 42.33 | 44.70 | a | 53.50 | 55.90 | 56.39 | 51.87 | 43.52 | 32.70 | 30.55 | 44.46 | |||||||||||
| 1979 | 25.58 | 35.14 | 39.19 | 41.50 | 47.61 | 50.13 | 55.39 | 55.29 | ----- | z | ----- | z | 37.57 | 38.68 | 42.61 | |||||||||||
| 1980 | 28.58 | 34.46 | a | 36.57 | c | 41.36 | b | 44.93 | a | 48.72 | a | 55.17 | g | 51.79 | b | 50.14 | a | 43.39 | c | 41.60 | 37.15 | d | 41.70 | |||
| 1981 | 35.41 | d | 35.35 | h | 38.96 | d | 42.00 | a | 46.30 | a | 51.22 | c | 53.23 | e | 57.00 | b | 51.00 | 42.10 | 40.15 | c | 36.11 | c | 44.86 | |||
| 1982 | 33.48 | 35.93 | 34.77 | 36.93 | 45.10 | 53.17 | 52.65 | 54.32 | 50.77 | 45.45 | 35.50 | 35.07 | d | 42.76 | ||||||||||||
| 1983 | 36.78 | h | 38.82 | 42.74 | 39.67 | 48.03 | 51.87 | 54.55 | 56.16 | 48.07 | 42.32 | 42.56 | c | 30.80 | a | 45.05 | ||||||||||
| 1984 | 33.35 | 37.38 | 41.65 | 40.43 | 43.84 | 48.70 | 54.16 | 52.52 | 50.27 | 43.81 | 38.87 | 31.94 | 43.08 | |||||||||||||
| 1985 | 28.35 | 33.18 | 36.84 | 43.70 | 46.07 | a | 52.33 | 56.94 | 54.10 | 48.97 | 42.26 | 30.64 | e | 26.68 | 41.67 | |||||||||||
| 1986 | 36.74 | 38.04 | 43.61 | 40.33 | 46.32 | 53.77 | 53.65 | 57.35 | ----- | z | 45.68 | 39.70 | 33.65 | 44.44 | ||||||||||||
| 1987 | 32.16 | 38.75 | 40.42 | 43.33 | 48.71 | 52.90 | 55.71 | 56.87 | 52.27 | 45.97 | 41.27 | 33.87 | 45.19 | |||||||||||||
| 1988 | 33.42 | 36.55 | 38.29 | 43.93 | 45.61 | 52.07 | 56.16 | 56.10 | 50.50 | 51.45 | 40.77 | 35.26 | 45.01 | |||||||||||||
| 1989 | 36.77 | 28.14 | 37.58 | 43.63 | 47.32 | 53.93 | 55.35 | 55.48 | 52.30 | 45.81 | 42.20 | 35.52 | 44.50 | |||||||||||||
| 1990 | 37.48 | 33.79 | 40.81 | 45.53 | 46.61 | 52.83 | 58.42 | 58.94 | 56.63 | 44.84 | 39.87 | 28.71 | 45.37 | |||||||||||||
| 1991 | 31.35 | 38.54 | 36.06 | 41.27 | 46.06 | 51.30 | 56.90 | 56.58 | 54.43 | 43.87 | 42.10 | 35.94 | 44.53 | |||||||||||||
| 1992 | 37.97 | 38.06 | k | 41.74 | 45.77 | 49.16 | 54.43 | 58.03 | 56.71 | 49.79 | b | 47.23 | 39.63 | 33.97 | 46.77 | |||||||||||
| 1993 | 31.00 | a | 31.46 | 39.26 | 43.63 | 51.26 | 52.20 | 54.32 | 56.81 | 51.80 | 46.65 | 32.13 | 33.61 | 43.68 | ||||||||||||
| 1994 | 38.27 | i | 30.21 | 39.68 | 43.40 | 48.39 | 50.43 | 54.94 | 54.90 | 54.33 | 41.48 | 33.87 | 35.94 | 44.32 | ||||||||||||
| 1995 | 35.81 | 38.50 | 36.65 | 39.30 | 47.42 | 50.87 | 56.77 | 52.77 | 55.87 | 44.16 | 42.20 | 34.93 | a | 44.60 | ||||||||||||
| 1996 | 34.52 | 32.03 | 37.19 | 43.00 | 46.00 | 51.20 | 57.97 | 55.84 | 50.87 | 43.97 | 38.70 | 36.84 | 44.01 | |||||||||||||
| 1997 | 34.23 | 35.71 | 38.06 | 39.67 | 48.71 | 50.40 | 54.90 | 57.26 | 52.70 | 43.90 | a | 39.20 | 33.42 | 44.01 | ||||||||||||
| 1998 | 36.13 | 38.86 | 40.81 | 40.63 | 45.97 | 51.43 | 57.68 | 55.39 | 52.37 | 44.87 | 40.60 | 33.45 | 44.85 | |||||||||||||
| 1999 | 36.29 | c | 36.15 | a | 36.79 | c | 39.03 | 39.90 | b | 48.32 | b | 52.74 | d | 58.58 | e | 52.10 | i | 41.08 | e | 38.38 | d | 33.61 | 41.90 | |||
| 2000 | 30.27 | a | 33.35 | c | 34.34 | b | 40.46 | b | 43.59 | d | 51.53 | 52.52 | 55.44 | d | 52.78 | c | 43.29 | g | 35.07 | a | 31.40 | a | 41.89 | |||
| 2001 | 33.60 | a | 30.88 | b | 36.20 | a | 38.30 | c | 44.45 | i | 48.61 | b | 52.56 | d | 54.76 | b | 50.45 | h | 43.96 | f | 38.35 | g | 35.00 | g | 42.13 | |
| 2002 | 35.10 | k | 34.30 | h | 35.31 | o | 34.97 | 43.65 | 47.67 | c | 54.77 | 51.68 | 49.40 | j | 42.29 | 36.07 | 34.84 | 43.24 | ||||||||
| 2003 | 36.42 | 33.39 | 38.54 | g | 39.07 | 42.52 | 52.03 | 54.77 | 53.68 | c | 49.48 | e | 48.71 | c | 33.93 | p | 33.78 | d | 44.39 | |||||||
| 2004 | 31.26 | l | 36.40 | n | 38.19 | d | 40.13 | 40.78 | d | 50.24 | e | 54.42 | g | 55.06 | 46.89 | k | 44.35 | e | 32.75 | j | 32.48 | h | 44.79 | |||
| 2005 | ----- | z | 28.96 | c | 38.48 | 38.00 | g | 47.97 | 47.78 | g | 56.42 | 54.24 | f | 45.89 | l | 48.00 | k | 35.63 | 33.32 | 40.13 | ||||||
| 2006 | 38.44 | f | 31.61 | e | 36.77 | 41.47 | ----- | z | 53.74 | k | 54.68 | 53.52 | 49.23 | 41.25 | g | 39.43 | b | 33.58 | 42.54 | |||||||
| 2007 | 29.30 | a | 36.32 | 38.84 | 37.42 | f | 44.00 | 49.27 | 56.42 | 53.94 | 49.28 | a | 41.97 | 35.73 | 34.52 | 42.69 | ||||||||||
| 2008 | 31.03 | 33.41 | 32.87 | 36.20 | 45.44 | d | 47.77 | d | 52.79 | g | 54.84 | 51.00 | 47.62 | w | 40.35 | d | 31.26 | 40.42 | ||||||||
| 2009 | 30.45 | 30.21 | 32.67 | a | 36.30 | 44.30 | a | 51.87 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 37.63 | |||||
| 2010 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 47.92 | e | 53.73 | e | 55.92 | e | 51.10 | 45.06 | 36.77 | 35.61 | 46.59 | |||||
| 2011 | 34.16 | 31.12 | c | 37.90 | 35.97 | a | 43.39 | c | 49.50 | b | 53.14 | b | 54.80 | f | 54.08 | f | 44.11 | c | 37.14 | b | 32.15 | e | 39.86 | |||
| 2012 | 32.44 | d | 34.50 | e | 36.67 | d | 40.46 | d | 45.15 | e | 50.71 | i | 56.09 | h | 54.82 | i | 51.53 | k | 44.33 | g | 41.54 | b | 36.74 | d | 38.21 | |
| 2013 | 30.50 | e | 35.55 | f | 37.08 | e | 44.00 | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 33.79 | |
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 33.05 | 34.41 | 38.08 | 40.72 | 45.72 | 51.00 | 55.09 | 55.41 | 51.53 | 44.39 | 38.33 | 33.96 | 44.03 | |||||||||||||
| S.D. | 3.28 | 3.16 | 2.56 | 2.72 | 2.41 | 1.90 | 1.78 | 1.80 | 2.05 | 2.22 | 3.11 | 2.53 | 1.06 | |||||||||||||
| SKEW | -0.38 | -0.21 | 0.03 | -0.25 | -0.18 | -0.13 | 0.16 | -0.22 | 0.75 | 1.19 | -0.72 | -0.71 | -0.74 | |||||||||||||
| MAX | 37.97 | 38.86 | 43.61 | 45.77 | 51.26 | 54.43 | 58.42 | 58.94 | 56.63 | 51.45 | 42.56 | 38.68 | 45.37 | |||||||||||||
| MIN | 25.58 | 28.14 | 32.67 | 34.97 | 39.90 | 47.67 | 52.35 | 51.68 | 48.07 | 41.08 | 30.64 | 26.68 | 41.67 | |||||||||||||
| NO YRS | 30 | 30 | 34 | 33 | 33 | 33 | 31 | 33 | 27 | 29 | 33 | 34 | 14 | |||||||||||||