| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1937 | ----- | z | 28.39 | 35.32 | 35.57 | 45.61 | 51.63 | 61.66 | 55.58 | 48.80 | ----- | z | 35.37 | 29.85 | 42.78 | |||||||||||
| 1938 | 26.81 | 25.68 | 28.31 | 36.91 | c | 45.17 | d | 53.81 | a | 59.71 | 55.27 | e | 54.02 | f | 41.65 | a | 28.33 | g | 27.52 | c | 40.08 | |||||
| 1939 | 24.29 | c | 24.17 | d | 31.00 | g | 42.95 | a | 46.30 | h | 48.23 | h | 58.79 | b | 58.65 | 50.35 | c | 41.46 | c | 34.74 | g | 29.48 | b | 41.27 | ||
| 1940 | 27.46 | c | 30.10 | 35.87 | d | 42.73 | 52.45 | 58.00 | 57.94 | 60.98 | 51.88 | b | 44.38 | e | 31.47 | a | 29.55 | 43.57 | ||||||||
| 1941 | 28.02 | 31.86 | 38.06 | 39.93 | 47.45 | 50.42 | 61.06 | 57.48 | 46.55 | 41.55 | 36.63 | 28.05 | 42.26 | |||||||||||||
| 1942 | 25.18 | 25.29 | 31.95 | 39.57 | 42.84 | 50.48 | 59.94 | 59.03 | 51.55 | 42.95 | 31.65 | 28.05 | 40.71 | |||||||||||||
| 1943 | 23.02 | 29.50 | 32.27 | 42.02 | 42.82 | 47.78 | 58.79 | 54.85 | 55.75 | 41.48 | 36.43 | 28.10 | 41.07 | |||||||||||||
| 1944 | 21.84 | 26.47 | 32.23 | 37.37 | 45.95 | 50.02 | 58.00 | 54.89 | 51.95 | 46.55 | 31.78 | 26.39 | 40.29 | |||||||||||||
| 1945 | 28.34 | 31.30 | 31.04 | g | 35.42 | j | 46.20 | a | 52.00 | b | 62.11 | 59.50 | a | 50.90 | 46.24 | 31.05 | 26.31 | 43.40 | ||||||||
| 1946 | 22.05 | a | 26.00 | 32.47 | 41.42 | 47.48 | 51.12 | 58.74 | 60.08 | a | 49.38 | 36.66 | 31.60 | 31.03 | 40.67 | |||||||||||
| 1947 | 24.44 | 34.73 | 37.45 | 41.22 | 50.79 | 49.09 | a | 56.69 | 54.73 | 50.17 | 43.60 | 31.57 | 27.61 | 41.84 | ||||||||||||
| 1948 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 55.97 | a | 53.89 | 48.27 | 41.66 | 31.03 | 19.02 | 41.64 | ||||||
| 1949 | 13.35 | 25.30 | 32.77 | 41.88 | 48.31 | 52.24 | a | 57.03 | 55.18 | 51.25 | 37.10 | 37.18 | 21.65 | 39.44 | ||||||||||||
| 1950 | 18.92 | k | ----- | z | ----- | z | ----- | z | 53.50 | x | 53.67 | 60.81 | 59.55 | 52.18 | 44.07 | a | 37.12 | 36.58 | 49.14 | |||||||
| 1951 | 24.27 | 31.77 | 30.45 | 43.69 | a | ----- | z | 59.25 | 59.81 | w | 59.81 | r | 54.90 | 42.23 | 32.80 | 22.84 | 38.02 | |||||||||
| 1952 | 22.08 | 27.12 | 29.65 | 41.78 | 48.00 | 51.57 | 61.77 | 58.24 | 56.70 | 48.79 | 28.55 | 26.44 | 41.72 | |||||||||||||
| 1953 | 32.32 | a | 31.84 | 32.77 | 38.22 | a | 41.85 | 48.37 | 60.68 | 56.31 | 56.03 | 42.56 | 37.78 | 30.10 | 42.40 | |||||||||||
| 1954 | 27.53 | 34.30 | 30.10 | 41.20 | 50.19 | 50.55 | 58.66 | 53.87 | 49.77 | 42.58 | 38.38 | 28.13 | 42.11 | |||||||||||||
| 1955 | 24.10 | 26.12 | 30.40 | 34.02 | 45.11 | 55.19 | a | 55.98 | 58.92 | 50.95 | 44.21 | 31.75 | 27.97 | 40.39 | ||||||||||||
| 1956 | 27.02 | 24.28 | 31.81 | 41.33 | 49.08 | 50.48 | 60.71 | 55.90 | 51.17 | 41.23 | 33.18 | 30.05 | 41.35 | |||||||||||||
| 1957 | 17.58 | 31.55 | 34.89 | 39.95 | 46.75 | a | 55.30 | 56.97 | 53.65 | 53.90 | 40.94 | 30.42 | 31.18 | 41.09 | ||||||||||||
| 1958 | 28.44 | 34.48 | 30.56 | 37.75 | 52.76 | 54.78 | 62.07 | b | 61.97 | 50.38 | 45.44 | 36.20 | 34.55 | 44.11 | ||||||||||||
| 1959 | 30.19 | 29.93 | 35.92 | 43.02 | 42.95 | 53.90 | 62.02 | 55.79 | b | 49.43 | 44.94 | 36.10 | 25.92 | 42.51 | ||||||||||||
| 1960 | 24.34 | 27.33 | 35.35 | 39.48 | 43.76 | 55.70 | 64.11 | 55.50 | 53.80 | 44.19 | 32.95 | 27.68 | 42.02 | |||||||||||||
| 1961 | 30.52 | 32.52 | 33.34 | 40.80 | 45.56 | 59.87 | 61.44 | 62.45 | 49.05 | 43.56 | 32.68 | 27.23 | 43.25 | |||||||||||||
| 1962 | 24.60 | 29.23 | 32.11 | 43.55 | 43.42 | 52.93 | 57.73 | 55.90 | 54.28 | 43.71 | 36.72 | 31.19 | 42.11 | |||||||||||||
| 1963 | 26.11 | 38.55 | 34.48 | 34.57 | 49.68 | 52.75 | 56.77 | 57.87 | 55.80 | 44.15 | 33.55 | 31.06 | 42.95 | |||||||||||||
| 1964 | 26.02 | 26.97 | ----- | z | 37.45 | 45.27 | 51.93 | 60.42 | 57.23 | 50.77 | 46.71 | 31.27 | 27.47 | 41.95 | ||||||||||||
| 1965 | 29.39 | 32.50 | 35.45 | 41.72 | 45.52 | 54.28 | 60.18 | 57.90 | 48.25 | 47.15 | 35.32 | 25.13 | 42.73 | |||||||||||||
| 1966 | 26.32 | 27.07 | 33.21 | 41.37 | 50.35 | 52.33 | a | 57.50 | 59.44 | 54.63 | 44.60 | a | 35.97 | 29.60 | 42.70 | |||||||||||
| 1967 | 29.10 | 31.07 | 31.21 | 33.28 | 47.55 | 55.52 | 62.61 | 64.18 | 57.48 | a | 44.00 | b | 36.17 | 23.90 | e | 43.01 | ||||||||||
| 1968 | 26.98 | 34.45 | a | 35.53 | 37.55 | 45.47 | 54.42 | 62.19 | 55.18 | 52.72 | a | 42.82 | 32.95 | a | 24.37 | 42.05 | ||||||||||
| 1969 | 23.55 | a | 26.12 | 31.90 | 37.50 | a | 51.19 | 56.12 | 59.10 | 57.45 | 52.52 | 39.23 | 36.43 | 29.87 | 41.75 | |||||||||||
| 1970 | 28.35 | 32.59 | 34.23 | 34.27 | 47.73 | 56.88 | 61.52 | 59.71 | 48.50 | 40.95 | 34.62 | 23.60 | 41.91 | |||||||||||||
| 1971 | 26.98 | 28.66 | 29.52 | a | 37.05 | 47.18 | 51.82 | 61.42 | 62.19 | 49.08 | 41.31 | 33.12 | 22.74 | 40.92 | ||||||||||||
| 1972 | 22.79 | 29.79 | 36.34 | 36.68 | 49.66 | 55.65 | 61.77 | 60.31 | 48.93 | 43.11 | 31.13 | 21.02 | 41.43 | |||||||||||||
| 1973 | 21.32 | 30.38 | 31.85 | 41.00 | 50.31 | 54.47 | 60.26 | 59.03 | 53.75 | 41.92 | 30.80 | 30.11 | 42.10 | |||||||||||||
| 1974 | 22.00 | 26.93 | 31.69 | 36.92 | 44.26 | 58.08 | 60.24 | 60.39 | 55.43 | 43.84 | 34.80 | c | 27.27 | 41.82 | ||||||||||||
| 1975 | 26.05 | 27.30 | 30.24 | 33.38 | 45.48 | 50.85 | 61.45 | 55.73 | 55.58 | 41.34 | 30.60 | 30.45 | 40.71 | |||||||||||||
| 1976 | 27.42 | 28.26 | 31.26 | 35.97 | 48.89 | 49.93 | 59.53 | 54.92 | 53.65 | 45.15 | 37.82 | 24.47 | 41.44 | |||||||||||||
| 1977 | 22.63 | 32.70 | 31.79 | 42.40 | 41.55 | 57.88 | 59.24 | 62.50 | 50.63 | 44.65 | 33.53 | 28.76 | 42.35 | |||||||||||||
| 1978 | 31.82 | 30.50 | 39.25 | a | 38.52 | 44.31 | 53.83 | 59.95 | 58.74 | 49.67 | 46.11 | 26.93 | 19.16 | 41.57 | ||||||||||||
| 1979 | 18.40 | 30.12 | 37.08 | 38.62 | 49.73 | 54.60 | 60.31 | 57.85 | 56.25 | 47.40 | 31.87 | 29.08 | 42.61 | |||||||||||||
| 1980 | 25.15 | 34.28 | 34.10 | 41.50 | 45.32 | a | 49.97 | 62.26 | 56.53 | 54.30 | 45.21 | 35.53 | 29.73 | 42.82 | ||||||||||||
| 1981 | 32.42 | 32.16 | c | 36.08 | 42.73 | 46.29 | 55.00 | 58.94 | 61.82 | 53.00 | 42.97 | 38.43 | 28.77 | e | 44.05 | |||||||||||
| 1982 | 22.61 | 26.95 | 32.26 | n | 34.08 | j | 47.16 | l | 56.54 | e | 59.03 | 60.52 | 51.28 | 42.89 | 29.08 | j | 25.50 | l | 45.69 | |||||||
| 1983 | 30.09 | o | 30.44 | j | 35.43 | j | 36.56 | l | 49.45 | l | 51.22 | a | 57.44 | 59.37 | 51.17 | a | 43.98 | j | 34.97 | m | 25.28 | m | 54.80 | |||
| 1984 | 27.44 | m | 30.50 | n | 36.67 | k | 36.19 | l | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 35.08 | r | 30.13 | 19.95 | 25.04 | |||
| 1985 | 26.94 | 27.84 | 29.84 | 40.64 | i | 47.35 | 55.72 | 64.40 | 57.60 | f | 48.55 | a | 43.82 | a | 27.19 | q | 25.80 | k | 43.06 | |||||||
| 1986 | 33.60 | u | 31.12 | l | 39.21 | q | 39.58 | k | 47.25 | m | 58.30 | 57.55 | 63.44 | 48.05 | 45.59 | i | 33.74 | m | 27.22 | m | 56.83 | |||||
| 1987 | 24.28 | m | 30.91 | l | 35.16 | l | 48.95 | i | 51.05 | 57.19 | d | 56.73 | 59.83 | a | ----- | z | 50.00 | 40.53 | k | 29.77 | p | 54.96 | ||||
| 1988 | 26.04 | s | 30.10 | s | 37.39 | q | 45.64 | s | 46.65 | r | 53.47 | k | 62.69 | b | 60.25 | a | 53.60 | 51.60 | 33.60 | a | 26.33 | a | 48.01 | |||
| 1989 | 27.53 | m | 21.21 | i | 35.26 | l | 45.63 | k | 45.55 | i | 55.83 | 58.61 | 56.39 | 53.57 | 43.66 | 36.13 | k | 32.33 | m | 53.61 | ||||||
| 1990 | 28.26 | n | 26.39 | i | 35.62 | o | 46.64 | l | ----- | z | 53.97 | 62.92 | 60.44 | 57.57 | 44.08 | ----- | z | ----- | z | 55.79 | ||||||
| 1991 | 28.45 | k | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 63.27 | 62.32 | 58.77 | ----- | z | ----- | z | ----- | z | 61.45 | ||||
| 1992 | ----- | z | 36.77 | r | ----- | z | ----- | z | 55.05 | a | 57.28 | ----- | z | 60.42 | r | ----- | z | ----- | z | 38.62 | z | 20.75 | s | 56.17 | ||
| 1993 | 18.00 | w | 25.61 | s | 37.65 | n | 39.50 | o | 50.08 | m | 50.71 | m | 53.26 | j | 57.15 | 53.82 | 49.32 | 25.93 | 27.95 | l | 46.55 | |||||
| 1994 | 28.75 | m | 27.03 | j | 40.25 | k | 39.19 | v | 44.10 | z | 50.28 | e | 66.74 | n | 62.50 | x | 58.07 | i | 43.31 | 25.78 | a | 20.43 | x | 39.79 | ||
| 1995 | 30.61 | v | 33.23 | m | 34.11 | m | 40.25 | l | 47.73 | 53.15 | 60.06 | 57.81 | ----- | z | 42.32 | 38.88 | 34.44 | m | 49.99 | |||||||
| 1996 | 27.84 | 31.90 | 37.08 | 40.52 | 44.55 | a | 54.12 | 63.73 | 61.10 | 50.12 | 41.92 | 35.30 | 28.39 | 43.05 | ||||||||||||
| 1997 | 25.19 | 29.30 | 36.66 | 38.92 | 51.61 | 51.62 | 59.79 | ----- | z | 53.32 | 43.18 | 35.47 | 24.35 | 40.86 | ||||||||||||
| 1998 | 31.42 | 30.52 | 35.02 | 39.78 | 42.94 | 53.07 | 64.13 | 62.63 | 56.68 | 42.37 | 32.75 | 23.16 | 42.87 | |||||||||||||
| 1999 | 26.85 | 26.70 | a | 32.53 | 36.90 | 45.03 | 51.80 | 58.79 | 59.73 | 53.90 | 45.34 | 37.13 | 28.76 | 41.96 | ||||||||||||
| 2000 | 26.93 | a | 33.06 | m | 32.87 | h | 43.57 | b | 46.06 | n | 56.43 | h | 60.91 | o | 60.41 | i | 55.32 | p | 42.10 | k | 29.00 | f | 27.34 | f | 35.25 | |
| 2001 | 28.14 | b | 29.26 | a | 36.73 | a | 37.76 | a | 52.48 | c | 51.26 | a | 59.62 | a | 63.55 | c | 54.25 | d | 45.42 | a | 35.07 | 26.50 | e | 43.34 | ||
| 2002 | 26.15 | 30.80 | 32.42 | 42.80 | 46.56 | 56.93 | 64.58 | 57.00 | 53.13 | 41.11 | 34.02 | 29.34 | 42.90 | |||||||||||||
| 2003 | 32.76 | 30.66 | 36.90 | 37.70 | 47.39 | 57.18 | 65.15 | 61.55 | i | 55.85 | g | 46.92 | e | 30.26 | e | 29.26 | 41.42 | |||||||||
| 2004 | 29.10 | 28.81 | 40.20 | h | 42.82 | 46.69 | 55.42 | 62.37 | ----- | z | 51.02 | 43.50 | 33.22 | 30.76 | 42.37 | |||||||||||
| 2005 | 28.10 | 30.36 | 38.76 | 40.12 | 48.40 | 49.83 | 62.54 | f | 60.54 | f | 52.98 | h | 43.44 | 32.02 | 24.08 | 37.23 | ||||||||||
| 2006 | 26.87 | 26.48 | 29.69 | 39.78 | e | 49.34 | 57.73 | 64.66 | i | 58.82 | 54.02 | e | 43.18 | 32.63 | 25.92 | 40.41 | ||||||||||
| 2007 | 24.16 | f | 30.77 | 38.92 | 40.23 | 49.34 | 54.42 | 65.19 | 60.06 | f | 50.87 | 40.40 | 34.73 | 23.68 | 42.86 | |||||||||||
| 2008 | 20.22 | f | 29.07 | 31.56 | 35.41 | h | 48.11 | 52.45 | 61.71 | 60.33 | e | 53.38 | 43.19 | g | 37.17 | 24.13 | 44.21 | |||||||||
| 2009 | 28.33 | a | 29.38 | 32.13 | a | 38.23 | 49.50 | a | 54.07 | a | 62.43 | c | 59.05 | 55.62 | 40.63 | 31.68 | 21.52 | 41.88 | ||||||||
| 2010 | 33.08 | 31.57 | 34.24 | 36.30 | 41.85 | 51.13 | 60.76 | 57.47 | 51.65 | 45.52 | 30.78 | 28.05 | 41.87 | |||||||||||||
| 2011 | 26.23 | 26.61 | 32.65 | 34.63 | 41.61 | 51.00 | j | 56.08 | m | 60.26 | j | 56.11 | l | 42.74 | b | 31.07 | 26.08 | 32.70 | ||||||||
| 2012 | 28.16 | 28.90 | 31.29 | 40.18 | 45.97 | 50.15 | 59.26 | 60.63 | 54.95 | 43.47 | l | 34.41 | a | 26.05 | 41.81 | |||||||||||
| 2013 | 24.90 | a | 29.89 | s | 37.17 | m | 42.25 | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 12.50 | z | 24.90 | |
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 26.17 | 29.60 | 33.49 | 39.29 | 47.10 | 53.60 | 60.38 | 58.51 | 52.42 | 43.63 | 33.49 | 27.07 | 42.04 | |||||||||||||
| S.D. | 3.70 | 2.94 | 2.75 | 2.83 | 3.08 | 2.84 | 2.31 | 2.69 | 2.76 | 2.64 | 2.98 | 3.47 | 1.00 | |||||||||||||
| SKEW | -0.71 | 0.39 | 0.31 | -0.35 | 0.20 | 0.14 | 0.10 | 0.09 | 0.12 | 0.35 | -0.36 | -0.20 | -0.22 | |||||||||||||
| MAX | 33.08 | 38.55 | 39.25 | 43.69 | 55.05 | 59.87 | 65.19 | 64.18 | 58.77 | 51.60 | 38.88 | 36.58 | 44.11 | |||||||||||||
| MIN | 13.35 | 24.17 | 28.31 | 33.28 | 41.55 | 47.78 | 55.97 | 53.65 | 46.55 | 36.66 | 25.78 | 19.02 | 39.44 | |||||||||||||
| NO YRS | 60 | 61 | 56 | 58 | 61 | 68 | 67 | 64 | 66 | 67 | 64 | 63 | 44 | |||||||||||||