| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1957 | ----- | z | ----- | z | 47.75 | u | 55.39 | c | 65.02 | 71.28 | 73.11 | 71.85 | 68.33 | 51.67 | b | 40.75 | 41.61 | 59.89 | ||||||||
| 1958 | 37.82 | 46.04 | 44.10 | 52.12 | 67.26 | 73.65 | 79.58 | 79.87 | 65.53 | 54.53 | 42.10 | 36.40 | 56.58 | |||||||||||||
| 1959 | 34.50 | 37.73 | 47.15 | 53.60 | 57.32 | 69.08 | 76.63 | 71.68 | 62.92 | 53.55 | 37.40 | 33.27 | 52.90 | |||||||||||||
| 1960 | 23.89 | 38.71 | 45.23 | 53.88 | 59.06 | 69.75 | 81.37 | 72.40 | 66.55 | 56.13 | 43.80 | 31.03 | 53.48 | |||||||||||||
| 1961 | 35.92 | 45.93 | a | 47.82 | 53.35 | 60.68 | 74.73 | 79.26 | 79.42 | 62.32 | 52.18 | 35.63 | 35.56 | 55.23 | ||||||||||||
| 1962 | 31.47 | 38.04 | 42.73 | a | 56.62 | a | 57.68 | 67.78 | 75.18 | 72.94 | 66.83 | 54.35 | 45.55 | 38.66 | 53.99 | |||||||||||
| 1963 | 27.87 | 38.29 | 46.76 | 51.33 | 60.94 | 68.33 | 72.50 | 75.32 | 70.85 | 57.90 | 45.90 | 32.82 | 54.07 | |||||||||||||
| 1964 | 39.34 | 40.33 | 44.00 | 51.43 | 59.23 | 67.18 | 75.45 | 70.52 | 63.75 | 53.13 | 41.25 | 31.29 | 53.07 | |||||||||||||
| 1965 | 35.87 | 42.11 | 42.61 | 56.20 | 60.16 | 67.25 | 75.13 | 74.45 | 62.58 | 58.13 | 46.30 | 35.74 | 54.71 | |||||||||||||
| 1966 | 37.31 | 39.71 | 46.85 | 54.28 | 63.19 | 66.92 | 73.08 | 74.74 | 69.52 | 55.31 | 45.68 | 40.81 | 55.62 | |||||||||||||
| 1967 | 43.37 | 44.43 | 45.84 | 49.68 | 60.56 | 70.12 | 77.69 | 79.81 | 72.23 | 56.53 | 42.57 | 36.29 | 56.59 | |||||||||||||
| 1968 | 37.26 | 42.55 | 49.34 | 51.28 | 61.50 | 68.95 | 78.02 | 72.50 | 66.57 | 52.71 | 43.02 | 33.69 | 54.78 | |||||||||||||
| 1969 | 23.00 | 33.91 | 45.18 | 52.83 | 62.89 | 71.73 | 73.35 | 71.60 | 65.90 | 51.34 | 43.93 | 36.48 | 52.68 | |||||||||||||
| 1970 | 33.79 | 41.86 | 45.13 | 49.30 | 60.34 | 70.58 | 76.39 | 74.05 | 61.35 | 51.92 | 41.98 | 36.05 | 53.56 | |||||||||||||
| 1971 | 39.19 | 40.89 | 42.63 | 51.43 | 60.95 | 63.57 | 74.71 | 79.00 | 60.95 | 52.48 | 43.60 | 36.87 | 53.86 | |||||||||||||
| 1972 | 35.08 | 37.40 | 48.48 | 48.68 | 61.26 | 67.37 | 73.48 | ----- | z | 62.83 | 53.32 | 42.15 | 29.68 | 50.89 | ||||||||||||
| 1973 | 30.98 | 38.34 | 47.71 | 52.72 | 61.23 | 67.50 | 74.65 | 73.56 | 64.65 | 54.27 | 42.00 | 40.56 | 54.01 | |||||||||||||
| 1974 | 29.40 | 43.62 | 46.42 | 52.28 | 57.76 | 69.00 | 72.13 | 73.34 | 66.67 | 53.53 | 45.52 | 41.13 | 54.23 | |||||||||||||
| 1975 | 35.94 | 36.07 | 43.53 | 48.03 | 58.69 | 64.67 | 76.37 | 70.42 | 64.93 | 54.56 | 42.53 | a | 37.60 | 52.78 | ||||||||||||
| 1976 | 37.74 | 39.83 | 43.26 | 50.55 | 60.15 | 63.52 | 72.50 | 69.98 | 67.23 | 53.23 | 41.68 | 33.73 | 52.78 | |||||||||||||
| 1977 | 27.31 | 41.54 | 45.13 | 57.13 | 56.40 | 70.07 | 71.82 | 76.13 | 61.38 | 51.74 | 40.80 | 37.35 | 53.07 | |||||||||||||
| 1978 | 32.44 | 39.50 | 46.95 | a | 51.70 | 57.21 | 67.10 | 72.03 | 71.52 | a | 62.62 | 52.34 | 35.20 | 31.98 | 51.72 | |||||||||||
| 1979 | 18.56 | d | 36.36 | 45.61 | 51.98 | ----- | z | 67.42 | ----- | z | 73.63 | 66.65 | 57.40 | 38.71 | a | 39.32 | a | 49.56 | ||||||||
| 1980 | ----- | z | ----- | z | 44.32 | 54.52 | 59.58 | 63.42 | 73.24 | 70.26 | 65.93 | 52.65 | a | 44.38 | 38.90 | 56.72 | ||||||||||
| 1981 | 38.52 | 39.95 | 47.55 | 52.55 | 59.48 | 63.47 | 71.65 | 75.53 | 65.05 | a | 51.69 | b | 44.22 | 36.26 | 53.83 | |||||||||||
| 1982 | 32.13 | 39.66 | 44.84 | 49.08 | 58.89 | 68.15 | 72.85 | 73.61 | 64.32 | 52.48 | 39.33 | 36.13 | 52.62 | |||||||||||||
| 1983 | 40.26 | 42.98 | 49.53 | 52.32 | 62.21 | c | 66.18 | 70.35 | 74.66 | 61.13 | 52.82 | 47.08 | 25.31 | 53.74 | ||||||||||||
| 1984 | 34.29 | 40.17 | 48.18 | 51.63 | ----- | z | 64.32 | 73.52 | 73.63 | 61.83 | 51.15 | 41.38 | 28.55 | 51.70 | ||||||||||||
| 1985 | 27.55 | 32.70 | 44.56 | 55.05 | 62.06 | 68.25 | 78.55 | ----- | z | 59.98 | 52.50 | ----- | z | 22.55 | a | 50.38 | ||||||||||
| 1986 | 34.61 | 39.30 | 49.42 | 51.68 | 60.23 | 71.45 | 69.67 | a | 76.78 | o | 57.35 | q | 54.82 | 44.53 | 33.81 | 50.95 | ||||||||||
| 1987 | 31.87 | 40.14 | 47.87 | 57.15 | 64.05 | 69.52 | 73.00 | 72.87 | 68.77 | 54.08 | 45.22 | 34.68 | 54.93 | |||||||||||||
| 1988 | 33.40 | 40.43 | 46.66 | 54.33 | 59.98 | 66.77 | 73.56 | 72.58 | 64.10 | 58.68 | 46.88 | 34.10 | 54.29 | |||||||||||||
| 1989 | 38.63 | 27.00 | 44.16 | 54.77 | 59.60 | 69.57 | 73.10 | 71.56 | 65.37 | 53.82 | 46.07 | 35.23 | 53.24 | |||||||||||||
| 1990 | 40.31 | 38.00 | 46.12 | j | 56.60 | 59.21 | 67.22 | 76.15 | 74.58 | 70.25 | 52.81 | 47.18 | 27.21 | 55.41 | ||||||||||||
| 1991 | 30.00 | 44.30 | 43.90 | 52.80 | 58.19 | 63.42 | 74.48 | 76.31 | ----- | z | 53.94 | 42.80 | 39.11 | 52.66 | ||||||||||||
| 1992 | 39.44 | 43.10 | ----- | z | 56.20 | 63.79 | 72.72 | 73.40 | 74.26 | 62.73 | 54.13 | 42.68 | 33.69 | 56.01 | ||||||||||||
| 1993 | 24.21 | 30.25 | 40.47 | k | 53.18 | 64.55 | ----- | z | 68.71 | 70.89 | 65.78 | 56.27 | 37.38 | 37.60 | 50.88 | |||||||||||
| 1994 | 40.19 | 36.62 | 48.24 | 56.72 | ----- | z | 67.13 | 77.40 | 76.68 | 68.48 | 53.95 | 41.92 | 37.35 | 54.97 | ||||||||||||
| 1995 | 34.19 | 43.12 | 45.60 | 52.25 | 60.97 | 65.33 | 73.71 | 69.82 | 67.15 | 52.18 | 46.00 | 35.73 | 53.84 | |||||||||||||
| 1996 | 33.56 | 32.36 | 44.92 | 53.92 | 57.26 | 65.95 | 75.06 | 72.06 | 63.23 | 53.60 | 41.65 | 32.37 | 52.16 | |||||||||||||
| 1997 | 34.55 | 39.93 | 47.40 | 51.22 | 62.03 | 65.95 | 72.65 | 75.10 | 65.62 | 53.58 | 43.67 | 37.71 | 54.12 | |||||||||||||
| 1998 | 37.19 | 42.82 | 47.71 | 52.53 | 60.48 | 67.62 | 78.84 | 74.74 | 70.15 | 52.52 | 47.63 | 36.18 | 55.70 | |||||||||||||
| 1999 | 41.19 | 43.21 | 46.16 | 50.35 | 56.90 | 65.97 | 70.65 | 72.95 | 63.55 | 52.42 | 47.20 | 41.29 | 54.32 | |||||||||||||
| 2000 | 37.27 | 39.40 | 46.27 | 55.22 | 60.53 | 65.50 | a | 73.45 | 73.65 | 63.28 | 52.40 | 37.20 | 32.95 | 53.09 | ||||||||||||
| 2001 | 34.16 | 36.77 | 47.06 | 51.42 | 61.61 | 64.58 | 74.00 | b | 75.17 | a | 67.30 | 53.03 | 44.95 | a | 38.96 | c | 54.08 | |||||||||
| 2002 | 38.55 | 39.07 | 42.94 | 52.85 | 57.27 | 68.42 | 75.56 | 71.31 | 64.53 | 51.40 | 42.58 | 40.45 | 53.74 | |||||||||||||
| 2003 | 40.87 | 40.48 | 50.47 | 53.60 | 59.74 | 69.53 | 77.26 | 75.29 | 67.23 | 58.37 | 39.83 | 36.94 | 55.80 | |||||||||||||
| 2004 | 30.47 | 38.43 | 50.42 | 55.30 | 61.47 | 68.40 | 76.48 | 75.34 | 64.60 | 55.95 | 42.77 | 38.45 | 54.84 | |||||||||||||
| 2005 | 32.92 | 38.04 | 49.58 | ----- | z | 63.02 | 66.32 | 75.19 | 74.85 | 63.98 | 56.08 | 42.35 | 31.50 | 53.98 | ||||||||||||
| 2006 | 43.09 | i | 36.84 | 45.81 | 53.07 | 61.05 | 68.25 | 77.77 | 72.94 | 65.77 | 53.58 | 44.05 | 33.23 | 55.67 | ||||||||||||
| 2007 | 31.84 | 39.11 | 48.10 | 52.45 | 61.74 | 67.53 | 77.85 | 72.31 | 64.40 | 52.69 | 42.92 | 37.69 | 54.05 | |||||||||||||
| 2008 | 31.56 | 41.52 | 44.85 | 48.48 | 60.82 | 65.33 | 75.29 | 72.39 | 63.78 | 52.11 | 44.92 | 30.40 | 52.62 | |||||||||||||
| 2009 | 35.10 | 36.29 | 42.55 | 52.50 | 60.44 | 68.63 | 75.77 | 75.00 | 66.50 | 50.55 | 44.13 | 28.61 | 53.01 | |||||||||||||
| 2010 | 39.24 | 41.89 | 47.53 | 50.83 | 57.34 | 65.18 | 73.05 | 72.44 | 64.92 | 54.66 | 41.58 | 35.84 | 53.71 | |||||||||||||
| 2011 | 36.31 | 36.52 | b | 45.79 | 48.18 | b | 57.12 | c | 64.34 | a | 69.56 | 74.69 | 67.23 | b | 55.29 | b | 42.75 | 33.66 | 52.62 | |||||||
| 2012 | 35.79 | 38.93 | b | 46.42 | 53.77 | 59.12 | a | 64.21 | a | 74.60 | 73.81 | ----- | z | 53.84 | ----- | z | ----- | z | 55.61 | |||||||
| 2013 | 32.42 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 32.42 | ||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 34.27 | 39.31 | 46.18 | 52.77 | 60.38 | 67.57 | 74.56 | 73.77 | 65.29 | 53.79 | 42.88 | 35.10 | 53.90 | |||||||||||||
| S.D. | 5.03 | 3.65 | 2.11 | 2.34 | 2.28 | 2.64 | 2.68 | 2.37 | 2.70 | 1.93 | 2.91 | 4.06 | 1.13 | |||||||||||||
| SKEW | -0.86 | -0.88 | 0.09 | -0.03 | 0.51 | 0.46 | 0.21 | 0.72 | 0.38 | 0.87 | -0.68 | -0.78 | 0.53 | |||||||||||||
| MAX | 43.37 | 46.04 | 50.47 | 57.15 | 67.26 | 74.73 | 81.37 | 79.87 | 72.23 | 58.68 | 47.63 | 41.61 | 56.59 | |||||||||||||
| MIN | 18.56 | 27.00 | 42.55 | 48.03 | 56.40 | 63.42 | 68.71 | 69.82 | 59.98 | 50.55 | 35.20 | 22.55 | 51.72 | |||||||||||||
| NO YRS | 54 | 54 | 52 | 55 | 53 | 55 | 55 | 53 | 53 | 56 | 54 | 55 | 41 | |||||||||||||