| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1963 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 35.93 | c | 35.93 | |
| 1964 | 39.13 | 37.22 | b | 36.62 | g | ----- | z | ----- | z | ----- | z | ----- | z | 50.23 | 48.97 | 47.35 | 40.77 | 41.23 | 43.56 | |||||||
| 1965 | 39.81 | 38.54 | 38.26 | 42.83 | 42.26 | 47.00 | 50.03 | 53.00 | 49.00 | a | 46.94 | 45.97 | 39.39 | 44.42 | ||||||||||||
| 1966 | 40.38 | b | 37.08 | b | 39.48 | 42.43 | 42.39 | 48.43 | 51.39 | 51.00 | 51.07 | 46.16 | 44.93 | 41.52 | 44.69 | |||||||||||
| 1967 | 40.71 | 42.00 | a | ----- | z | 43.27 | o | 46.05 | j | 50.11 | b | 51.94 | 52.21 | b | 51.43 | 46.19 | d | 44.71 | b | 38.32 | 46.40 | |||||
| 1968 | 39.10 | a | 44.79 | 43.03 | 40.53 | 45.10 | a | 50.77 | 51.34 | b | 52.86 | b | ----- | z | 43.22 | d | 43.17 | a | 39.00 | b | 44.81 | |||||
| 1969 | 37.17 | a | 37.35 | k | 39.18 | t | 39.86 | b | 45.81 | 51.43 | 48.81 | 45.23 | 47.64 | b | 44.44 | f | 40.47 | 40.32 | 44.08 | |||||||
| 1970 | 40.21 | g | 38.96 | 38.87 | 37.27 | 43.65 | 47.67 | 48.97 | 48.68 | 45.87 | 41.71 | 43.50 | 42.68 | 43.44 | ||||||||||||
| 1971 | 39.69 | o | 37.64 | 36.55 | 38.41 | a | 42.42 | 47.17 | a | 50.87 | 52.87 | a | 49.41 | a | 43.71 | 41.50 | 37.61 | 43.47 | ||||||||
| 1972 | 36.10 | 41.36 | a | 42.87 | 40.03 | 44.23 | e | 46.93 | a | 51.31 | b | 51.61 | 47.50 | 45.06 | 42.33 | 37.03 | 43.86 | |||||||||
| 1973 | 38.26 | 41.46 | 39.42 | 39.30 | 44.60 | a | 47.38 | a | 48.39 | 46.48 | 50.28 | a | 44.52 | 43.17 | 43.58 | 43.90 | ||||||||||
| 1974 | 37.55 | 38.18 | 40.75 | c | 42.07 | b | 42.38 | e | 47.29 | b | 49.40 | a | 50.74 | 49.71 | b | 41.67 | g | 43.04 | c | 38.67 | d | 43.62 | ||||
| 1975 | 38.88 | g | 40.42 | b | 39.06 | 37.83 | 43.50 | a | 48.18 | b | 51.47 | a | 51.13 | 50.29 | b | 46.37 | a | 41.57 | 39.48 | d | 44.48 | |||||
| 1976 | 38.97 | b | 38.24 | d | 36.84 | 38.58 | f | 41.62 | o | 46.96 | c | 50.91 | h | 52.40 | f | 49.86 | h | 45.21 | l | 44.36 | h | 34.90 | k | 40.25 | ||
| 1977 | 35.88 | f | 42.00 | d | 37.68 | f | 41.38 | i | 42.91 | h | 49.21 | k | 50.00 | q | 51.75 | o | ----- | z | ----- | z | 43.27 | 43.39 | 42.88 | |||
| 1978 | 44.39 | 42.86 | 44.16 | 42.73 | 44.61 | 51.37 | 51.94 | 51.90 | 51.67 | 48.35 | 37.03 | 35.23 | 45.52 | |||||||||||||
| 1979 | 36.61 | 40.96 | 42.77 | 43.10 | 47.77 | 48.23 | 53.13 | 54.42 | 55.13 | 51.42 | 42.47 | 44.06 | 46.67 | |||||||||||||
| 1980 | 38.06 | 43.38 | 41.00 | 42.63 | 45.42 | 49.93 | 53.00 | a | 50.77 | 49.77 | 46.94 | 44.10 | 43.32 | 45.69 | ||||||||||||
| 1981 | 42.68 | 42.00 | 41.84 | 41.97 | 46.16 | 51.70 | 51.35 | 53.32 | 51.83 | 46.33 | a | 44.60 | 44.13 | 46.49 | ||||||||||||
| 1982 | 37.06 | 38.86 | 40.26 | 39.83 | 44.55 | 49.97 | 53.35 | 54.13 | 52.60 | 49.32 | 42.80 | 41.13 | 45.32 | |||||||||||||
| 1983 | 42.26 | 36.00 | z | 42.09 | t | 41.86 | w | 47.55 | 50.33 | 54.00 | 54.45 | 52.53 | 47.00 | 46.43 | 42.77 | 48.59 | ||||||||||
| 1984 | 40.61 | 42.24 | 44.19 | 42.67 | 45.03 | 49.60 | 52.87 | 53.26 | 50.00 | 47.61 | 43.50 | 36.61 | 45.68 | |||||||||||||
| 1985 | 36.39 | 38.43 | 39.23 | 43.60 | 44.74 | 49.73 | 51.26 | 51.90 | 49.53 | 45.48 | 37.53 | 35.23 | 43.59 | |||||||||||||
| 1986 | 42.65 | 44.39 | 44.13 | 41.83 | 45.68 | 51.13 | 52.16 | 51.10 | 49.87 | 47.65 | 44.37 | 40.97 | 46.33 | |||||||||||||
| 1987 | 41.29 | 41.18 | 42.03 | 43.50 | 48.52 | b | 50.31 | a | 51.74 | 52.06 | 50.23 | 48.52 | 45.17 | 41.00 | 46.30 | |||||||||||
| 1988 | 40.06 | 40.38 | 40.10 | 44.10 | 46.35 | 49.57 | 52.74 | 50.58 | 48.67 | 50.61 | 45.20 | 38.90 | 45.61 | |||||||||||||
| 1989 | 38.52 | 34.57 | 42.35 | 45.30 | 46.29 | 50.47 | 53.71 | 54.26 | 48.53 | 44.77 | 41.93 | 39.74 | 45.04 | |||||||||||||
| 1990 | 41.00 | 37.93 | 42.29 | 44.63 | 47.23 | 50.33 | 53.81 | 53.55 | 53.50 | 45.45 | 42.63 | 33.16 | 45.46 | |||||||||||||
| 1991 | 38.19 | 44.79 | 38.39 | 42.27 | 44.81 | 48.37 | 52.42 | 53.94 | 50.93 | 47.13 | 44.67 | 40.10 | 45.50 | |||||||||||||
| 1992 | 41.90 | 44.21 | 44.84 | 47.37 | 47.90 | 51.17 | 54.32 | 52.16 | 50.63 | 48.87 | 44.33 | 39.19 | 47.24 | |||||||||||||
| 1993 | 36.55 | 38.54 | 46.19 | 45.73 | 49.00 | 51.10 | 52.84 | 53.58 | 49.67 | 47.23 | 38.40 | 40.00 | 45.74 | |||||||||||||
| 1994 | 41.16 | 39.39 | 42.03 | 44.40 | 48.61 | 49.47 | 51.39 | 53.39 | 51.53 | 45.61 | 37.10 | 40.03 | 45.34 | |||||||||||||
| 1995 | 45.06 | 44.50 | 41.97 | 42.13 | 47.65 | 49.70 | 54.81 | 52.48 | 53.47 | 46.81 | 46.97 | 44.58 | 47.51 | |||||||||||||
| 1996 | 42.13 | 42.59 | 41.06 | 45.33 | 46.55 | 49.33 | 51.65 | 51.13 | 49.33 | 45.94 | 42.80 | 42.00 | 45.82 | |||||||||||||
| 1997 | 39.84 | 38.89 | 42.35 | 43.43 | 49.42 | 50.53 | 55.10 | 54.48 | 54.30 | 47.81 | 46.03 | 38.32 | 46.71 | |||||||||||||
| 1998 | 46.13 | 43.25 | 43.19 | 42.60 | 47.00 | 51.73 | 54.26 | 54.10 | 50.03 | 45.03 | 43.70 | 38.16 | 46.60 | |||||||||||||
| 1999 | 39.45 | 41.00 | 37.97 | 41.20 | 44.35 | 49.37 | 50.84 | 54.37 | d | 51.87 | 47.35 | k | 48.11 | c | 42.20 | a | 45.52 | |||||||||
| 2000 | 43.10 | 45.10 | 40.74 | 44.59 | a | 47.52 | 49.80 | 51.52 | 49.55 | 46.53 | 45.65 | 44.53 | 45.58 | 46.18 | ||||||||||||
| 2001 | 47.13 | 39.39 | 42.74 | 42.67 | 47.58 | 49.50 | 52.52 | 53.65 | 49.40 | 46.68 | 44.57 | 41.26 | 46.42 | |||||||||||||
| 2002 | 38.87 | 40.81 | a | 39.45 | 44.25 | b | 45.97 | 50.33 | 53.70 | a | 50.93 | a | 48.53 | 43.94 | 43.53 | 43.06 | 45.28 | |||||||||
| 2003 | 45.29 | 38.89 | 45.42 | 44.30 | 46.74 | 50.33 | 54.10 | 53.87 | 51.87 | 50.77 | 42.70 | 41.58 | 47.16 | |||||||||||||
| 2004 | 42.94 | 42.10 | 43.32 | 45.70 | 48.35 | 52.33 | 54.71 | ----- | z | 51.17 | 47.68 | 41.33 | 42.55 | 46.56 | ||||||||||||
| 2005 | 41.26 | 38.39 | 43.26 | 44.13 | 50.03 | 51.60 | 54.26 | 52.32 | 49.50 | 47.16 | 42.47 | 42.06 | 46.37 | |||||||||||||
| 2006 | 45.06 | 37.61 | 40.61 | 43.23 | 46.19 | 52.90 | 54.19 | 51.45 | 48.63 | 44.97 | 44.53 | 39.71 | 45.76 | |||||||||||||
| 2007 | 35.74 | 41.68 | 43.61 | 42.43 | 46.55 | 49.30 | 54.26 | 55.06 | 49.90 | 47.39 | 40.63 | 38.68 | 45.44 | |||||||||||||
| 2008 | 37.71 | 38.45 | 37.97 | 39.53 | 46.68 | 47.77 | 50.39 | 53.74 | 48.37 | 46.77 | 45.53 | 37.61 | 44.21 | |||||||||||||
| 2009 | 36.58 | 38.96 | 39.84 | 40.70 | 45.16 | 50.13 | 51.84 | 51.52 | 51.20 | 46.39 | 42.37 | 36.29 | 44.25 | |||||||||||||
| 2010 | 46.26 | 44.71 | 40.74 | 41.67 | 44.84 | 50.93 | 51.39 | 52.58 | 52.27 | 47.39 | 42.07 | 43.71 | 46.55 | |||||||||||||
| 2011 | 39.65 | 37.82 | 43.97 | a | 41.27 | 44.90 | 50.80 | 53.47 | a | 54.17 | a | 50.32 | b | 48.81 | 40.70 | 36.32 | 45.18 | |||||||||
| 2012 | 38.84 | 39.08 | c | 39.94 | 44.70 | 45.35 | 48.60 | 54.39 | 52.23 | 48.30 | 48.10 | 46.07 | 39.19 | 45.40 | ||||||||||||
| 2013 | 36.35 | 38.36 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 37.36 | |||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 40.30 | 40.49 | 41.34 | 42.50 | 45.94 | 49.73 | 52.33 | 52.23 | 50.28 | 46.75 | 43.11 | 40.13 | 45.65 | |||||||||||||
| S.D. | 3.04 | 2.54 | 2.33 | 2.21 | 1.92 | 1.52 | 1.69 | 2.01 | 1.92 | 1.94 | 2.43 | 2.79 | 0.97 | |||||||||||||
| SKEW | 0.50 | 0.17 | -0.07 | -0.35 | -0.03 | -0.28 | -0.40 | -1.39 | 0.24 | 0.03 | -0.67 | -0.25 | -0.30 | |||||||||||||
| MAX | 47.13 | 45.10 | 46.19 | 47.37 | 50.03 | 52.90 | 55.10 | 55.06 | 55.13 | 51.42 | 48.11 | 45.58 | 47.51 | |||||||||||||
| MIN | 35.74 | 34.57 | 36.55 | 37.27 | 42.26 | 46.93 | 48.39 | 45.23 | 45.87 | 41.71 | 37.03 | 33.16 | 43.59 | |||||||||||||
| NO YRS | 46 | 48 | 44 | 44 | 45 | 47 | 46 | 46 | 46 | 44 | 48 | 49 | 36 | |||||||||||||