| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1923 | ----- | z | ----- | z | ----- | z | ----- | z | 55.26 | 56.03 | 67.67 | a | 64.32 | 59.07 | 45.77 | 39.27 | 31.10 | 52.31 | d | |||||||
| 1924 | 26.48 | 37.52 | 33.68 | 43.97 | 57.06 | 62.53 | 66.74 | 64.03 | 56.67 | 44.23 | 35.10 | 29.45 | 46.46 | |||||||||||||
| 1925 | 30.87 | 37.96 | 39.13 | 45.87 | 53.16 | 59.76 | a | 68.45 | 63.16 | 55.27 | 46.39 | 35.60 | 33.87 | 47.46 | ||||||||||||
| 1926 | 30.90 | 36.61 | 43.48 | 48.80 | 55.42 | 64.73 | 67.29 | 65.10 | 56.37 | 49.35 | 41.73 | 31.03 | 49.24 | |||||||||||||
| 1927 | 31.00 | 34.96 | 38.06 | 44.17 | 51.42 | 60.80 | 67.81 | 64.13 | 57.20 | 47.81 | 38.97 | 30.23 | 47.21 | |||||||||||||
| 1928 | 30.77 | 33.31 | 41.42 | 46.00 | 55.58 | 61.90 | 65.87 | 65.47 | a | 59.20 | 47.10 | 37.40 | 29.32 | 47.78 | ||||||||||||
| 1929 | 28.68 | 30.00 | 37.00 | 39.66 | a | 52.35 | 58.67 | 68.83 | a | 68.94 | 56.40 | 48.94 | 37.07 | 34.35 | 46.74 | |||||||||||
| 1930 | 26.55 | 36.64 | 38.80 | a | 47.03 | 47.32 | 61.13 | 67.16 | 66.03 | 55.87 | 45.26 | 37.00 | 26.10 | 46.24 | ||||||||||||
| 1931 | 31.29 | 37.36 | 40.06 | 48.77 | 56.48 | 60.17 | 72.06 | 67.74 | 57.80 | 48.06 | 34.33 | 28.84 | 48.58 | |||||||||||||
| 1932 | 28.13 | 31.03 | 39.32 | 43.13 | 51.45 | 58.93 | 65.90 | 65.06 | 59.97 | 47.81 | 41.33 | 29.06 | 46.76 | |||||||||||||
| 1933 | 26.26 | 24.61 | 40.16 | 50.90 | 55.58 | 71.32 | b | 82.42 | 76.77 | 69.93 | b | 61.39 | 45.90 | a | 30.50 | a | 52.98 | |||||||||
| 1934 | 35.81 | 42.64 | 50.23 | 59.72 | a | 64.10 | 63.93 | 76.55 | 74.32 | 69.33 | 57.13 | a | 43.80 | 34.03 | 55.97 | |||||||||||
| 1935 | 28.83 | m | 39.75 | 40.06 | 50.70 | 59.00 | ----- | z | ----- | z | 61.58 | ----- | z | 40.16 | ----- | z | ----- | z | 48.54 | f | ||||||
| 1936 | 31.77 | 33.61 | a | 40.32 | 45.33 | 53.32 | 61.33 | 68.58 | 67.55 | 58.57 | 48.94 | 38.47 | 29.19 | 48.08 | ||||||||||||
| 1937 | 15.16 | 28.59 | a | 37.03 | 42.33 | 51.97 | 59.37 | 66.97 | 66.68 | 59.60 | 48.32 | 40.50 | 35.65 | 46.01 | ||||||||||||
| 1938 | 32.48 | 31.67 | a | 36.00 | 43.73 | 49.10 | 58.33 | 64.45 | 63.94 | 60.10 | 44.94 | 31.70 | 33.71 | 45.85 | ||||||||||||
| 1939 | 33.26 | 29.75 | 39.35 | 49.80 | 55.84 | 60.97 | 67.81 | 67.84 | 58.90 | 47.65 | 40.70 | 36.39 | 49.02 | |||||||||||||
| 1940 | 35.90 | a | 36.83 | 42.16 | 48.83 | 57.65 | 66.00 | 66.71 | 67.29 | 57.23 | 49.16 | 37.23 | 33.84 | 49.90 | ||||||||||||
| 1941 | 35.74 | 39.14 | 39.81 | 42.31 | a | 53.39 | 58.07 | 64.74 | 62.48 | 54.27 | 43.26 | 37.03 | 32.00 | 46.85 | ||||||||||||
| 1942 | 31.74 | 32.89 | 36.13 | 44.53 | 49.42 | 60.57 | 68.00 | 65.23 | 55.47 | 49.26 | 39.43 | 33.58 | 47.19 | |||||||||||||
| 1943 | 33.27 | a | 36.07 | 42.04 | c | 49.86 | a | 54.84 | 55.90 | 68.19 | 62.74 | 59.77 | 49.84 | 37.77 | 33.19 | 48.62 | ||||||||||
| 1944 | 30.16 | 30.24 | 37.48 | 42.47 | ----- | z | 55.76 | a | 62.87 | 62.55 | 58.57 | 49.97 | 38.07 | 32.03 | 45.47 | a | ||||||||||
| 1945 | 31.77 | 35.81 | a | 35.13 | a | 43.47 | 50.77 | 60.00 | 70.13 | 66.43 | a | 60.33 | 50.71 | 37.30 | 30.45 | 47.69 | ||||||||||
| 1946 | 30.19 | 32.04 | 37.45 | 46.43 | 54.52 | 60.87 | 67.45 | 66.55 | 58.97 | 43.97 | 31.73 | 35.77 | 47.16 | |||||||||||||
| 1947 | 29.48 | 35.57 | 39.26 | 45.10 | 55.13 | 60.73 | 65.52 | 62.94 | 59.63 | 48.94 | 32.90 | 29.94 | 47.09 | |||||||||||||
| 1948 | 30.48 | 29.07 | 31.29 | 43.00 | 49.65 | 59.33 | 63.94 | 62.55 | 57.03 | 47.81 | 34.10 | 26.06 | 44.53 | |||||||||||||
| 1949 | 18.50 | a | 25.71 | 34.97 | 48.13 | 52.35 | 62.90 | 67.16 | 63.61 | 59.83 | 45.71 | 40.33 | 27.00 | g | 47.20 | a | ||||||||||
| 1950 | 24.32 | 33.96 | 35.90 | 48.43 | 51.32 | 58.83 | 67.65 | 62.90 | 57.07 | 50.81 | 40.83 | 35.97 | 47.33 | |||||||||||||
| 1951 | 29.71 | 30.71 | 35.94 | 45.07 | 52.00 | 60.63 | 68.52 | 64.00 | 59.40 | 46.58 | 35.07 | 28.52 | 46.34 | |||||||||||||
| 1952 | 25.61 | 31.03 | 30.84 | 44.73 | 52.45 | 54.90 | 65.71 | 64.06 | 58.07 | 50.03 | 33.43 | 29.39 | 45.02 | |||||||||||||
| 1953 | 33.26 | 30.75 | 34.87 | 43.50 | 43.94 | 55.60 | 67.26 | 62.35 | 58.23 | 45.74 | 36.77 | 30.13 | 45.20 | |||||||||||||
| 1954 | 30.10 | a | 35.75 | 33.29 | 46.80 | 53.84 | 58.27 | 66.71 | 61.35 | 56.00 | 46.81 | 39.30 | 28.81 | 46.42 | ||||||||||||
| 1955 | 23.35 | 26.96 | 33.68 | 39.57 | 47.48 | 57.03 | a | 64.00 | 65.74 | 59.20 | 48.42 | 36.50 | 33.45 | 44.62 | ||||||||||||
| 1956 | 33.71 | 28.45 | 34.90 | 41.90 | 50.10 | 59.33 | 62.77 | 60.39 | 60.10 | 44.97 | 34.67 | 30.32 | 45.13 | |||||||||||||
| 1957 | 24.71 | 35.43 | 39.06 | 42.97 | 47.77 | 62.53 | 65.47 | a | 63.87 | 58.13 | 45.35 | 34.53 | 32.23 | 46.01 | ||||||||||||
| 1958 | 32.13 | a | 37.50 | 35.19 | 43.77 | 53.58 | 58.77 | 64.87 | 67.35 | 60.37 | 51.48 | 37.67 | 34.03 | 48.06 | ||||||||||||
| 1959 | 33.74 | 32.32 | 41.13 | 49.03 | 51.55 | 63.43 | 69.90 | 63.42 | 56.93 | 50.42 | 38.17 | 33.55 | 48.63 | |||||||||||||
| 1960 | 28.13 | 32.83 | 41.68 | 47.57 | 51.87 | 64.87 | 68.39 | 65.48 | 61.00 | 48.74 | 37.83 | 32.00 | 48.37 | |||||||||||||
| 1961 | 30.71 | 35.18 | 38.13 | 46.03 | 51.42 | 64.50 | 69.90 | 65.77 | 55.83 | 47.61 | 35.13 | 30.48 | 47.56 | |||||||||||||
| 1962 | 30.16 | 33.61 | 33.81 | 48.20 | 48.38 | b | 57.82 | b | 63.04 | c | 62.14 | c | 55.67 | c | 49.61 | 38.36 | b | 30.39 | 45.93 | |||||||
| 1963 | 25.03 | 37.93 | 34.00 | a | 38.15 | d | 51.52 | 55.20 | 61.71 | 61.61 | 57.67 | 50.87 | 37.59 | a | 29.48 | 45.06 | ||||||||||
| 1964 | 26.07 | d | 28.45 | g | 32.00 | f | 41.00 | d | 48.07 | a | 58.53 | 65.58 | 63.97 | 54.32 | b | 50.06 | 33.50 | h | 30.46 | c | 48.67 | c | ||||
| 1965 | 32.58 | 32.24 | g | 36.67 | a | 43.63 | 49.50 | a | 54.73 | ----- | z | 63.55 | 53.07 | 49.29 | 40.13 | 29.90 | a | 45.31 | b | |||||||
| 1966 | 26.21 | b | 28.77 | b | 37.55 | 44.89 | b | 54.68 | 61.10 | 64.30 | a | 66.16 | 56.97 | a | 47.75 | c | 38.57 | 33.30 | d | 46.69 | ||||||
| 1967 | 31.68 | c | 32.21 | 37.23 | 35.14 | a | 50.61 | 56.14 | a | 66.94 | 67.55 | 59.37 | 48.42 | 42.23 | 26.94 | 46.20 | ||||||||||
| 1968 | 27.65 | 37.17 | 37.19 | 42.17 | 51.50 | a | 60.93 | 66.23 | 60.90 | 57.34 | a | 47.68 | 35.93 | 25.00 | 45.81 | |||||||||||
| 1969 | 31.03 | 26.32 | 32.23 | 43.07 | 51.94 | 57.23 | 64.63 | a | 65.26 | 58.24 | a | 43.40 | a | 36.40 | 31.06 | 45.07 | ||||||||||
| 1970 | 29.71 | 35.57 | 37.23 | 39.07 | 51.87 | 59.87 | 67.71 | 66.97 | 54.00 | 44.81 | 37.30 | 27.83 | a | 45.99 | ||||||||||||
| 1971 | 29.10 | 32.00 | 34.45 | 41.23 | 46.77 | 56.97 | 65.81 | 65.90 | 56.38 | a | 42.48 | 34.55 | a | 24.77 | 44.20 | |||||||||||
| 1972 | 26.83 | a | 31.10 | 42.06 | 43.73 | 50.13 | 60.30 | 67.07 | a | 63.00 | 54.63 | 44.00 | 32.67 | 25.03 | 45.05 | |||||||||||
| 1973 | 25.29 | 31.50 | 33.17 | a | 42.48 | a | 52.50 | a | 60.73 | 65.26 | 63.06 | 54.77 | 45.47 | a | 34.67 | 29.52 | 44.87 | |||||||||
| 1974 | 25.13 | 30.71 | 38.42 | 40.43 | 51.52 | 59.20 | 65.06 | 62.06 | 59.63 | 47.10 | 36.67 | 28.32 | 45.36 | |||||||||||||
| 1975 | 27.29 | 30.14 | 32.42 | 35.43 | 48.65 | 59.07 | 64.40 | a | 60.71 | 59.10 | 43.94 | 34.10 | 30.47 | a | 43.81 | |||||||||||
| 1976 | 27.42 | 30.66 | 35.03 | a | 38.50 | 52.23 | 56.53 | 64.81 | 56.47 | a | 56.33 | 46.03 | 37.33 | 26.19 | 43.96 | |||||||||||
| 1977 | 26.74 | 33.57 | 31.00 | 43.70 | 42.77 | 62.00 | 64.55 | 64.45 | 55.90 | 48.00 | 38.10 | a | 34.00 | 45.40 | ||||||||||||
| 1978 | 33.06 | 33.48 | a | 39.68 | 39.30 | 46.90 | 58.62 | a | 61.93 | a | 63.10 | 53.57 | 50.03 | 32.47 | 24.68 | 44.74 | ||||||||||
| 1979 | 26.97 | 28.07 | 36.77 | 43.10 | 52.77 | a | 59.07 | 63.90 | 61.94 | 59.23 | 49.13 | 33.00 | a | 30.03 | b | 45.33 | ||||||||||
| 1980 | 32.48 | 34.52 | 35.16 | 41.68 | b | 46.48 | 55.76 | a | 64.87 | 63.07 | a | 56.76 | a | 47.23 | 36.43 | 32.74 | 45.60 | |||||||||
| 1981 | 31.35 | 32.86 | 36.52 | 44.87 | 51.77 | 63.48 | a | 65.81 | 65.39 | 59.87 | 43.37 | a | 38.10 | 32.47 | a | 47.15 | ||||||||||
| 1982 | 27.18 | c | 32.25 | 34.17 | a | 40.80 | 51.84 | 57.00 | a | 64.19 | 64.73 | a | 55.52 | a | 44.35 | 33.07 | 30.80 | a | 44.66 | |||||||
| 1983 | 30.06 | 34.14 | 36.03 | 38.38 | a | 48.90 | 58.55 | a | 61.19 | 63.55 | 58.93 | a | 47.10 | a | 36.21 | b | 32.03 | a | 45.42 | |||||||
| 1984 | 32.55 | 30.75 | a | 39.20 | a | 40.77 | 56.45 | 58.40 | 65.74 | 64.23 | 59.80 | ----- | z | 35.13 | 26.97 | b | 46.36 | a | ||||||||
| 1985 | 28.37 | a | 30.14 | 32.97 | 44.90 | a | 50.10 | 61.93 | a | 64.00 | 60.47 | a | 51.15 | c | 44.74 | 34.07 | 30.35 | 44.43 | ||||||||
| 1986 | 33.52 | 36.32 | 40.17 | b | 43.34 | a | 51.68 | 61.31 | a | 62.19 | 65.13 | 52.00 | b | 44.23 | a | 37.34 | a | 28.71 | 46.33 | |||||||
| 1987 | 27.23 | 31.85 | a | 36.32 | 44.63 | c | 51.00 | a | 60.47 | 61.37 | a | 63.39 | 56.61 | b | 49.74 | 36.00 | a | 26.70 | a | 45.44 | ||||||
| 1988 | 27.65 | 33.00 | a | 37.16 | 42.03 | 49.60 | a | 57.30 | 66.97 | 64.03 | 55.93 | 51.32 | 36.97 | a | 28.68 | 45.89 | ||||||||||
| 1989 | 26.42 | 29.54 | 40.00 | 50.13 | 53.00 | a | 60.90 | 66.58 | 61.65 | 55.77 | 44.45 | 35.93 | 28.68 | 46.09 | ||||||||||||
| 1990 | 27.29 | 29.68 | 38.94 | ----- | z | 52.14 | b | 60.23 | 66.07 | b | 62.90 | 58.07 | 47.86 | b | 36.64 | b | 22.50 | a | 45.67 | a | ||||||
| 1991 | 26.69 | b | 36.52 | a | 33.79 | c | 41.46 | b | 48.07 | b | 57.43 | 64.89 | c | 63.52 | 59.45 | a | 50.74 | 37.17 | 28.90 | b | 45.72 | |||||
| 1992 | 29.03 | a | 35.69 | 39.87 | 46.93 | 54.74 | 58.25 | b | 63.35 | 64.73 | a | 58.13 | 49.74 | 33.53 | 26.80 | a | 46.73 | |||||||||
| 1993 | 27.61 | 32.00 | a | 37.55 | b | 42.61 | b | 49.93 | a | 55.17 | a | 60.58 | 60.34 | b | 51.14 | i | 45.13 | h | 32.76 | a | 26.54 | g | 44.28 | c | ||
| 1994 | 27.62 | e | 28.88 | b | 41.00 | a | 44.30 | c | 49.21 | b | 60.14 | a | 66.32 | 65.74 | 54.89 | c | 43.38 | e | 29.14 | a | 27.91 | h | 46.42 | a | ||
| 1995 | 32.04 | f | 36.58 | d | 37.97 | b | 41.52 | a | 44.27 | e | 52.21 | a | 61.97 | 61.43 | a | 55.41 | a | 44.45 | b | 39.50 | 31.53 | a | 46.08 | a | ||
| 1996 | 30.94 | 35.41 | 36.94 | 43.00 | 50.39 | 57.93 | 65.06 | 63.26 | 55.93 | 45.35 | 35.73 | 31.90 | 45.99 | |||||||||||||
| 1997 | 32.42 | ----- | z | 36.52 | 42.00 | 53.77 | 58.23 | 60.13 | 62.35 | 58.10 | 42.55 | 35.10 | ----- | z | 48.12 | b | ||||||||||
| 1998 | 28.84 | 31.39 | 34.71 | 36.17 | 41.39 | 50.17 | 62.23 | 62.77 | 54.50 | 41.90 | 33.67 | ----- | z | 43.43 | a | |||||||||||
| 1999 | 30.06 | 29.86 | 34.55 | 38.27 | 47.71 | 54.47 | 62.03 | 59.29 | 54.20 | 45.42 | 35.87 | 30.97 | 43.56 | |||||||||||||
| 2000 | 31.71 | 33.24 | 36.61 | 43.87 | 52.45 | 58.47 | 60.81 | 61.87 | 53.93 | 44.13 | 29.47 | 27.26 | 44.48 | |||||||||||||
| 2001 | 26.00 | 26.96 | 35.32 | 37.70 | 51.65 | 56.30 | 58.71 | 62.58 | 55.23 | 47.16 | 34.93 | 27.77 | 43.36 | |||||||||||||
| 2002 | 25.32 | 27.89 | 30.42 | 41.10 | 46.68 | 58.23 | 64.19 | 59.45 | 54.10 | 41.55 | 35.50 | 28.42 | 42.74 | |||||||||||||
| 2003 | 32.23 | 29.21 | 34.81 | 36.50 | 47.29 | 57.33 | 65.00 | 62.32 | ----- | z | 48.39 | 30.33 | 26.84 | 42.75 | a | |||||||||||
| 2004 | 25.58 | 28.34 | 40.06 | 41.63 | 49.00 | 57.43 | 62.00 | 59.84 | 51.63 | 42.94 | 33.23 | 27.90 | 43.30 | |||||||||||||
| 2005 | 31.45 | 33.86 | 35.87 | 35.50 | 46.58 | 53.40 | ----- | z | 60.35 | 50.10 | 44.65 | 34.97 | 31.55 | 41.66 | a | |||||||||||
| 2006 | 29.61 | 31.57 | 31.71 | 40.90 | a | 52.13 | 59.50 | 66.47 | a | 57.26 | 45.62 | a | 30.13 | a | 23.86 | p | 22.79 | b | 42.52 | a | ||||||
| 2007 | 11.05 | j | 20.38 | d | ----- | z | 40.33 | u | 41.90 | k | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 39.85 | c | 28.65 | 29.62 | i | |
| 2008 | 29.87 | a | 32.43 | a | 38.10 | 42.73 | 51.06 | 58.80 | 67.24 | j | 66.04 | e | 58.84 | k | 48.19 | 44.43 | i | 31.35 | 44.29 | c | ||||||
| 2009 | 34.93 | c | 34.07 | 35.00 | i | 41.87 | 58.77 | 58.20 | 69.90 | a | 64.94 | 61.37 | 46.45 | 38.17 | 29.68 | 48.94 | a | |||||||||
| 2010 | 32.74 | 35.82 | 38.13 | 40.55 | a | 48.03 | 61.90 | 69.45 | 64.21 | c | 56.79 | a | 51.35 | 36.23 | 34.06 | 47.44 | ||||||||||
| 2011 | 31.06 | 32.50 | 38.29 | 43.00 | 46.12 | n | 57.50 | 64.68 | 63.84 | 59.73 | 47.81 | 33.17 | 28.39 | 45.45 | a | |||||||||||
| 2012 | 29.62 | b | 34.10 | 37.35 | 45.20 | 53.42 | 59.83 | 65.58 | 69.13 | a | 62.59 | a | 49.97 | 39.63 | 32.68 | 48.26 | ||||||||||
| 2013 | 28.13 | 30.75 | 41.71 | 47.23 | 55.52 | 64.73 | 72.23 | a | 66.19 | 63.21 | a | 44.43 | c | 37.03 | 28.13 | a | 48.28 | |||||||||
| 2014 | 32.77 | 35.86 | 41.58 | 46.27 | 52.23 | 62.37 | 68.32 | 59.74 | 57.03 | 46.42 | 35.10 | 31.52 | 47.43 | |||||||||||||
| 2015 | 30.32 | 35.75 | 39.26 | 40.57 | 46.26 | 59.24 | a | 59.65 | 63.00 | 55.63 | 48.39 | 31.03 | 23.90 | b | 44.42 | |||||||||||
| 2016 | 25.84 | 30.66 | 37.23 | 42.47 | 46.06 | 60.33 | 62.61 | 60.44 | v | 51.67 | 45.13 | 32.53 | 25.87 | 41.85 | a | |||||||||||
| 2017 | 27.58 | 35.07 | m | 37.15 | d | 39.80 | 45.97 | 55.67 | 62.18 | t | 59.16 | ----- | z | 45.81 | ----- | z | ----- | z | 44.45 | e | ||||||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 29.30 | 32.64 | 37.21 | 43.49 | 51.27 | 59.26 | 65.83 | 63.90 | 57.28 | 47.00 | 36.38 | 30.04 | 46.41 | |||||||||||||
| S.D. | 3.45 | 3.65 | 3.23 | 3.96 | 3.70 | 3.12 | 3.44 | 2.99 | 3.39 | 3.62 | 3.04 | 3.03 | 2.07 | |||||||||||||
| SKEW | -0.90 | -0.25 | 0.51 | 0.63 | 0.17 | 0.40 | 1.41 | 1.03 | 0.42 | -0.30 | 0.21 | -0.19 | 1.68 | |||||||||||||
| MAX | 35.90 | 42.64 | 50.23 | 59.72 | 64.10 | 71.32 | 82.42 | 76.77 | 69.93 | 61.39 | 45.90 | 36.39 | 55.97 | |||||||||||||
| MIN | 15.16 | 20.38 | 30.42 | 35.14 | 41.39 | 50.17 | 58.71 | 56.47 | 45.62 | 30.13 | 29.14 | 22.50 | 42.74 | |||||||||||||
| YRS | 91 | 90 | 91 | 92 | 92 | 93 | 89 | 93 | 89 | 92 | 90 | 88 | 73 | |||||||||||||