| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1923 | ----- | z | ----- | z | ----- | z | ----- | z | 68.39 | 68.97 | 80.47 | a | 76.55 | 71.22 | 58.66 | 50.63 | 41.60 | 64.56 | d | |||||||
| 1924 | 38.76 | 50.95 | 45.73 | 56.98 | 69.95 | 76.68 | 79.97 | 78.85 | 72.35 | 58.31 | 48.47 | 40.16 | 59.76 | |||||||||||||
| 1925 | 42.34 | 49.18 | 52.24 | 58.03 | 64.77 | a | 71.98 | a | 81.35 | 77.08 | 68.50 | 59.69 | 48.20 | 45.65 | 59.92 | |||||||||||
| 1926 | 42.87 | 47.79 | 55.42 | 60.50 | 68.13 | 79.52 | 81.21 | 80.00 | 71.53 | 63.63 | 54.50 | 39.53 | 62.05 | |||||||||||||
| 1927 | 42.27 | 45.89 | 50.29 | 57.05 | 65.44 | 74.97 | 82.15 | 77.82 | 70.70 | 62.48 | 52.33 | 41.21 | 60.22 | |||||||||||||
| 1928 | 43.26 | 45.97 | 54.11 | 59.48 | 69.19 | 76.38 | 81.05 | 80.22 | a | 74.70 | 61.32 | 50.08 | 39.84 | 61.30 | ||||||||||||
| 1929 | 40.69 | 41.89 | 50.77 | 53.43 | b | 66.77 | 72.63 | 81.95 | b | 81.97 | 70.79 | a | 65.40 | a | 52.43 | 47.81 | 60.55 | |||||||||
| 1930 | 36.73 | 49.55 | 50.72 | b | 59.67 | 58.63 | 75.88 | 80.90 | 79.23 | 69.57 | 59.34 | 50.25 | 38.40 | 59.07 | ||||||||||||
| 1931 | 42.47 | 47.41 | 53.97 | 61.18 | 69.76 | 73.48 | 86.27 | 80.77 | 70.73 | 61.19 | 45.85 | 37.79 | 60.91 | |||||||||||||
| 1932 | 37.13 | 42.03 | 52.95 | 56.57 | 64.66 | 73.60 | 80.66 | 79.71 | 74.68 | 61.60 | 54.38 | 39.37 | 59.78 | |||||||||||||
| 1933 | 36.22 | a | 36.82 | 52.08 | 59.90 | 62.92 | 81.33 | c | 91.21 | 85.47 | 79.07 | b | 71.23 | 55.16 | b | 40.24 | b | 62.64 | ||||||||
| 1934 | 45.58 | 51.07 | 61.85 | 69.68 | b | 73.23 | 73.78 | 85.39 | 84.27 | 77.88 | 64.98 | b | 53.08 | 42.47 | 65.27 | |||||||||||
| 1935 | 38.12 | s | 47.62 | 48.39 | 58.15 | 66.11 | ----- | z | ----- | z | 75.63 | ----- | z | 54.24 | ----- | z | ----- | z | 58.36 | f | ||||||
| 1936 | 41.32 | 42.04 | b | 51.45 | 57.50 | 65.52 | 73.50 | 79.79 | 79.37 | 70.27 | 59.24 | 48.50 | 37.32 | 58.82 | ||||||||||||
| 1937 | 22.16 | 37.98 | b | 46.73 | 53.27 | 65.27 | 71.45 | 79.97 | 79.73 | 72.63 | 60.02 | 50.10 | 43.72 | a | 56.92 | |||||||||||
| 1938 | 41.66 | 38.85 | b | 43.61 | 55.07 | 61.13 | 70.62 | 77.00 | 76.65 | 72.02 | 56.19 | 41.53 | 40.98 | 56.28 | ||||||||||||
| 1939 | 39.77 | 39.36 | 50.19 | 62.30 | 68.29 | 74.87 | 81.58 | 81.79 | 70.98 | 60.58 | 52.77 | 47.68 | 60.85 | |||||||||||||
| 1940 | 45.00 | b | 45.86 | 54.02 | 60.40 | 71.10 | 80.20 | 80.31 | 81.47 | 69.30 | 62.27 | 48.18 | 41.90 | 61.67 | ||||||||||||
| 1941 | 43.27 | 46.70 | 49.94 | 53.11 | b | 66.21 | 71.10 | 78.87 | 75.19 | 67.67 | 55.69 | 49.65 | 40.84 | 58.19 | ||||||||||||
| 1942 | 40.66 | 42.70 | 49.11 | 56.53 | 63.52 | 75.37 | 83.26 | 80.53 | 70.82 | 62.66 | 51.98 | 45.63 | 60.23 | |||||||||||||
| 1943 | 43.78 | a | 47.41 | 52.93 | d | 61.29 | a | 68.40 | 70.17 | 81.44 | 77.97 | 74.72 | 62.68 | 50.33 | 40.84 | 61.00 | ||||||||||
| 1944 | 39.77 | 39.41 | 49.84 | 54.92 | ----- | z | 68.91 | a | 78.00 | 78.87 | 73.98 | 63.16 | 47.97 | 42.66 | 57.95 | a | ||||||||||
| 1945 | 43.13 | 47.02 | b | 46.65 | a | 57.68 | 64.48 | 74.20 | 84.13 | 78.82 | a | 74.52 | 61.45 | 48.88 | 40.37 | 60.11 | ||||||||||
| 1946 | 41.83 | a | 44.89 | a | 50.34 | 60.95 | 67.53 | 75.76 | a | 80.95 | 80.98 | 73.64 | a | 56.95 | a | 42.47 | 45.12 | b | 60.12 | |||||||
| 1947 | 42.18 | a | 48.88 | 53.67 | b | 58.55 | 70.00 | b | 74.24 | a | 80.15 | 76.74 | 75.45 | a | 61.77 | 45.48 | 40.20 | a | 60.61 | |||||||
| 1948 | 44.53 | b | 42.27 | a | 45.20 | d | 57.20 | e | 65.71 | g | 72.97 | 79.08 | 77.79 | 72.63 | 61.26 | 47.55 | 37.31 | 57.98 | a | |||||||
| 1949 | 28.02 | a | 38.32 | 46.47 | 61.12 | 64.45 | 76.18 | 80.85 | 77.66 | 74.88 | 59.82 | 54.10 | 38.23 | g | 60.17 | a | ||||||||||
| 1950 | 36.94 | 47.29 | 50.32 | 62.30 | 65.39 | 73.10 | 81.71 | 78.79 | 70.52 | 65.13 | 53.83 | 47.45 | 61.06 | |||||||||||||
| 1951 | 41.39 | 43.70 | 49.79 | 57.78 | 65.65 | 74.30 | 82.37 | 78.60 | 75.18 | 60.90 | 47.93 | 39.34 | 59.74 | |||||||||||||
| 1952 | 34.95 | 43.52 | 41.85 | 56.70 | 66.08 | f | 67.22 | 78.73 | 78.84 | c | 72.17 | 65.71 | 45.52 | 39.15 | 56.76 | a | ||||||||||
| 1953 | 45.73 | 43.91 | 49.29 | 56.60 | 56.65 | 70.08 | 81.84 | 77.31 | 73.25 | 59.58 | 49.72 | 42.53 | 58.87 | |||||||||||||
| 1954 | 41.32 | a | 48.84 | 45.84 | 61.23 | 68.55 | 71.93 | 81.02 | 75.37 | 71.45 | 61.65 | 51.68 | 39.31 | 59.85 | ||||||||||||
| 1955 | 33.69 | 39.59 | 47.77 | 52.67 | 61.24 | 71.40 | a | 77.61 | 79.63 | 73.68 | 63.34 | 49.37 | 43.97 | 57.83 | ||||||||||||
| 1956 | 44.11 | 41.05 | 50.55 | 54.37 | 63.42 | 74.38 | 77.58 | 75.35 | 74.75 | 58.42 | 47.60 | 43.21 | 58.73 | |||||||||||||
| 1957 | 34.37 | 47.16 | 50.87 | 55.65 | 60.34 | 76.77 | 79.50 | a | 77.81 | 71.80 | 56.77 | 45.50 | 42.29 | 58.24 | ||||||||||||
| 1958 | 42.45 | a | 47.02 | 44.21 | 54.93 | 67.23 | 73.02 | 78.76 | 80.92 | 73.73 | 65.27 | 49.78 | 46.05 | 60.28 | ||||||||||||
| 1959 | 44.10 | a | 41.64 | 53.94 | 62.25 | 63.84 | 77.35 | 84.15 | 77.18 | 69.93 | 63.89 | 50.97 | 43.39 | 61.05 | ||||||||||||
| 1960 | 36.55 | 42.71 | 54.55 | 59.53 | 65.18 | 79.03 | 82.10 | 79.71 | 74.85 | 60.65 | 47.60 | 41.56 | 60.33 | |||||||||||||
| 1961 | 41.89 | 46.18 | 49.85 | 58.85 | 63.65 | 78.10 | 83.18 | 77.73 | 69.02 | 60.02 | 46.15 | 39.31 | 59.49 | |||||||||||||
| 1962 | 40.74 | 42.43 | 44.27 | 62.33 | 61.26 | b | 72.84 | b | 77.72 | d | 78.46 | c | 71.96 | c | 62.85 | 51.95 | b | 42.74 | 59.13 | |||||||
| 1963 | 38.40 | 49.93 | 46.63 | a | 51.79 | d | 65.52 | 68.72 | 77.89 | 76.11 | 71.60 | 63.02 | 49.45 | a | 42.26 | 58.44 | ||||||||||
| 1964 | 38.56 | d | 43.20 | g | 46.32 | f | 55.13 | d | 62.38 | a | 72.67 | 80.48 | 78.31 | 69.93 | b | 65.77 | 45.82 | h | 42.79 | c | 62.89 | c | ||||
| 1965 | 43.27 | 46.29 | g | 48.53 | a | 53.60 | 62.35 | a | 68.83 | ----- | z | 77.90 | 66.98 | 64.94 | 50.35 | 39.47 | a | 57.62 | b | |||||||
| 1966 | 37.00 | b | 40.88 | b | 51.65 | 60.43 | b | 68.90 | 75.03 | 79.12 | a | 81.19 | 71.69 | a | 61.95 | c | 50.33 | 43.28 | d | 60.12 | ||||||
| 1967 | 42.95 | c | 45.82 | 50.37 | 46.31 | a | 64.56 | 70.38 | a | 81.52 | 82.19 | 71.63 | 63.81 | 53.43 | 36.97 | 59.16 | ||||||||||
| 1968 | 39.39 | 49.14 | 50.18 | 55.55 | 65.95 | a | 76.12 | 79.87 | 74.69 | 72.83 | a | 61.92 | 49.03 | 36.77 | 59.29 | |||||||||||
| 1969 | 42.23 | 37.02 | 44.65 | 56.52 | 66.97 | 70.93 | 79.73 | a | 81.40 | 73.79 | a | 57.37 | a | 49.17 | 43.10 | 58.57 | ||||||||||
| 1970 | 41.29 | 47.00 | 49.48 | 51.88 | 66.45 | 74.70 | 82.21 | 81.52 | 69.85 | 59.05 | 49.82 | 37.22 | a | 59.21 | ||||||||||||
| 1971 | 40.31 | 45.66 | 49.31 | 54.50 | 59.45 | 72.30 | 80.94 | 80.85 | 71.55 | a | 56.35 | 46.97 | a | 35.56 | 57.81 | |||||||||||
| 1972 | 38.62 | a | 46.19 | 57.37 | 57.33 | 65.23 | 74.27 | 82.92 | a | 77.84 | 68.83 | 56.15 | 44.33 | 37.10 | 58.85 | |||||||||||
| 1973 | 34.92 | 41.93 | 44.22 | a | 55.02 | a | 67.70 | a | 75.98 | 81.15 | 78.26 | 70.50 | 60.55 | a | 47.83 | 42.65 | 58.39 | |||||||||
| 1974 | 33.89 | 44.29 | 50.50 | 53.77 | 66.55 | 75.73 | 79.84 | 77.08 | 75.35 | 60.10 | 48.77 | 39.21 | 58.76 | |||||||||||||
| 1975 | 40.39 | 42.55 | 45.29 | 47.68 | 63.29 | 74.10 | 79.28 | a | 76.44 | 73.43 | 58.71 | 47.67 | 44.03 | a | 57.74 | |||||||||||
| 1976 | 41.31 | 42.91 | 48.27 | a | 51.93 | 66.50 | 71.60 | 79.55 | 72.02 | a | 69.03 | 60.32 | 51.72 | 40.34 | 57.96 | |||||||||||
| 1977 | 37.05 | 48.02 | 44.53 | 58.43 | 55.10 | 76.23 | 80.16 | 78.81 | 70.28 | 63.23 | 52.26 | a | 45.39 | 59.12 | ||||||||||||
| 1978 | 41.76 | 44.63 | a | 51.37 | 52.13 | 62.29 | 74.02 | a | 78.82 | a | 78.40 | 67.93 | 65.39 | 45.20 | 36.98 | 58.24 | ||||||||||
| 1979 | 36.68 | 39.88 | 49.15 | 56.88 | 67.02 | a | 74.77 | 79.65 | 76.34 | 74.78 | 62.85 | 47.22 | a | 42.76 | b | 59.00 | ||||||||||
| 1980 | 44.11 | 46.52 | 47.16 | 56.11 | b | 59.69 | 71.33 | a | 80.37 | 78.75 | a | 71.72 | a | 62.58 | 50.88 | 45.58 | 59.57 | |||||||||
| 1981 | 43.42 | 46.02 | 47.92 | 59.17 | 65.58 | 79.19 | a | 81.76 | 81.18 | 74.02 | 56.55 | a | 50.85 | 44.53 | a | 60.85 | ||||||||||
| 1982 | 38.54 | c | 45.32 | 46.08 | a | 54.52 | 65.87 | 70.98 | a | 78.23 | 79.08 | a | 68.76 | a | 58.06 | 44.95 | 40.92 | a | 57.61 | |||||||
| 1983 | 41.47 | 44.68 | 47.34 | 50.22 | a | 64.08 | 73.24 | a | 76.44 | 76.15 | 73.72 | a | 60.33 | a | 48.52 | b | 43.25 | a | 58.29 | |||||||
| 1984 | 44.31 | 45.00 | a | 53.50 | a | 54.68 | 71.89 | 73.43 | 79.84 | 77.66 | 74.08 | ----- | z | 46.85 | 35.30 | c | 59.69 | a | ||||||||
| 1985 | 39.82 | a | 43.24 | a | 46.74 | 60.57 | a | 65.81 | 78.26 | a | 80.95 | 77.63 | a | 65.98 | c | 59.37 | 46.47 | 40.85 | 58.81 | |||||||
| 1986 | 45.55 | 47.25 | 53.16 | b | 56.67 | a | 66.98 | 77.26 | a | 77.31 | 80.85 | 66.25 | b | 58.30 | a | 50.52 | a | 40.85 | 60.08 | |||||||
| 1987 | 38.56 | 44.69 | a | 48.47 | 60.61 | c | 64.98 | a | 75.97 | 76.38 | a | 78.85 | 72.32 | b | 63.95 | 47.81 | a | 36.33 | a | 59.08 | ||||||
| 1988 | 39.42 | 47.11 | a | 51.82 | 55.98 | 64.70 | a | 72.42 | 83.11 | 78.79 | 71.37 | 66.97 | 50.88 | a | 40.03 | 60.22 | ||||||||||
| 1989 | 37.98 | 41.18 | 54.42 | 65.08 | 67.35 | a | 75.58 | 82.69 | 76.94 | 71.05 | 59.31 | 51.05 | 43.03 | 60.47 | ||||||||||||
| 1990 | 41.00 | 42.61 | 53.35 | ----- | z | 65.91 | b | 75.67 | 81.71 | b | 77.97 | 72.40 | 63.52 | b | 49.93 | b | 35.60 | a | 59.97 | a | ||||||
| 1991 | 39.88 | b | 51.24 | a | 44.25 | c | 55.07 | b | 61.10 | b | 72.07 | 80.04 | c | 77.90 | 74.43 | a | 65.81 | 50.40 | 40.43 | b | 59.38 | |||||
| 1992 | 39.88 | a | 46.34 | 49.79 | 61.03 | 68.71 | 72.70 | b | 77.73 | 80.07 | a | 73.62 | 64.31 | 46.93 | 37.58 | a | 59.89 | |||||||||
| 1993 | 37.95 | 42.35 | b | 52.10 | b | 58.41 | b | 65.57 | a | 72.02 | a | 77.31 | 77.71 | b | 69.36 | i | 61.67 | h | 47.66 | a | 41.04 | g | 59.01 | c | ||
| 1994 | 43.15 | e | 41.62 | b | 55.74 | b | 59.37 | c | 64.62 | b | 77.88 | a | 83.06 | 82.34 | 71.78 | c | 59.58 | e | 42.47 | a | 41.39 | h | 61.96 | a | ||
| 1995 | 40.44 | f | 51.79 | d | 49.76 | b | 55.79 | a | 60.12 | f | 69.78 | a | 79.17 | a | 79.58 | a | 73.93 | a | 62.93 | b | 56.02 | 44.60 | a | 62.33 | b | |
| 1996 | 45.58 | 48.19 | 51.76 | 60.03 | 67.97 | 75.87 | 82.76 | 81.40 | 72.52 | 60.85 | 50.05 | 44.45 | 61.79 | |||||||||||||
| 1997 | 44.26 | ----- | z | 55.29 | 57.80 | 71.34 | 74.48 | 77.40 | 79.27 | 74.47 | a | 60.35 | 49.83 | ----- | z | 64.45 | b | |||||||||
| 1998 | 42.50 | 41.41 | 49.48 | 51.13 | 56.23 | 67.93 | 80.39 | 81.48 | 70.43 | a | 58.50 | 49.08 | ----- | z | 58.96 | a | ||||||||||
| 1999 | 44.19 | 44.98 | 50.27 | 52.28 | 64.50 | 72.64 | a | 78.44 | 76.26 | 72.45 | 64.92 | 52.60 | 45.61 | 59.93 | ||||||||||||
| 2000 | 45.47 | 46.17 | 51.02 | 60.47 | 69.89 | 76.57 | 78.76 | 79.24 | 71.90 | 60.29 | 44.87 | 42.56 | 60.60 | |||||||||||||
| 2001 | 37.74 | 37.98 | 50.10 | 53.27 | 70.10 | 74.33 | 75.68 | 79.76 | 73.23 | 64.97 | 49.58 | 39.92 | 58.89 | |||||||||||||
| 2002 | 39.73 | 45.68 | 47.39 | 58.45 | 64.16 | 78.18 | 83.71 | 78.19 | 72.50 | 59.24 | 50.15 | 40.11 | 59.79 | |||||||||||||
| 2003 | 46.45 | 42.61 | 50.60 | 51.42 | 64.13 | 75.77 | 84.31 | 78.65 | ----- | z | 67.08 | 44.52 | 40.13 | 58.70 | a | |||||||||||
| 2004 | 40.47 | 41.22 | 57.21 | 58.18 | 66.35 | 75.22 | 79.35 | 77.18 | 70.40 | 58.23 | 46.52 | 40.23 | 59.21 | |||||||||||||
| 2005 | 41.56 | 44.70 | 50.56 | 52.73 | 64.26 | 70.30 | ----- | z | 78.06 | 68.09 | a | 60.66 | 51.42 | 44.60 | 56.99 | a | ||||||||||
| 2006 | 43.27 | 47.52 | 45.65 | 54.79 | a | 69.29 | 77.75 | 84.05 | a | 79.92 | 69.79 | a | 53.57 | a | 47.39 | p | 38.36 | b | 60.36 | a | ||||||
| 2007 | 29.48 | j | 38.38 | d | ----- | z | 51.94 | u | 64.50 | k | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 56.89 | c | 42.06 | 45.78 | i | |
| 2008 | 41.53 | a | 46.82 | a | 54.95 | 60.25 | 67.11 | 77.60 | 84.62 | j | 83.62 | e | 77.68 | k | 66.78 | a | 59.88 | i | 44.60 | 60.36 | c | |||||
| 2009 | 49.07 | c | 46.68 | 52.02 | i | 59.30 | 76.19 | 73.85 | 87.25 | a | 81.97 | 80.23 | 62.77 | 55.53 | 42.84 | 65.06 | a | |||||||||
| 2010 | 44.68 | 49.09 | 53.68 | 55.83 | a | 63.84 | 79.07 | 86.24 | 81.39 | c | 75.91 | a | 65.35 | 52.00 | 45.90 | 62.75 | ||||||||||
| 2011 | 45.37 | 46.64 | 52.35 | 59.48 | 62.59 | n | 74.65 | 81.69 | 82.10 | 77.62 | 65.02 | 48.38 | 42.69 | 61.45 | a | |||||||||||
| 2012 | 45.83 | b | 48.48 | 52.77 | 61.35 | 71.10 | 78.15 | 81.31 | 85.85 | a | 80.34 | a | 67.84 | 55.85 | 46.10 | 64.58 | ||||||||||
| 2013 | 43.32 | 47.57 | 59.11 | 65.22 | a | 73.39 | 84.05 | 89.38 | a | 83.29 | 78.74 | a | 62.16 | c | 50.23 | 41.42 | a | 64.82 | ||||||||
| 2014 | 47.60 | 50.84 | 54.97 | 60.98 | 68.74 | 78.67 | 83.56 | 75.48 | 72.35 | 62.47 | 49.85 | 40.76 | 62.19 | |||||||||||||
| 2015 | 42.39 | 50.12 | 54.26 | 56.15 | 60.66 | 75.98 | a | 74.55 | 78.87 | 71.70 | 60.66 | 44.13 | 36.45 | b | 58.83 | |||||||||||
| 2016 | 37.15 | 45.81 | 51.60 | 56.55 | 60.73 | 77.52 | 79.77 | 76.83 | v | 67.62 | 58.77 | 46.38 | 37.03 | 56.27 | a | |||||||||||
| 2017 | 36.11 | 46.77 | m | 51.78 | d | 54.85 | 62.11 | 73.93 | 78.27 | t | 75.84 | ----- | z | 62.77 | ----- | z | ----- | z | 59.63 | e | ||||||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 40.78 | 44.85 | 50.33 | 57.16 | 65.59 | 74.35 | 80.81 | 78.98 | 72.28 | 61.48 | 49.40 | 41.36 | 59.85 | |||||||||||||
| S.D. | 4.03 | 3.58 | 3.69 | 3.81 | 3.74 | 3.13 | 2.79 | 2.39 | 2.87 | 3.20 | 3.15 | 3.02 | 1.67 | |||||||||||||
| SKEW | -1.40 | -0.28 | 0.21 | 0.04 | -0.17 | 0.17 | 0.90 | 0.30 | 0.43 | 0.09 | -0.01 | 0.01 | 1.03 | |||||||||||||
| MAX | 49.07 | 51.79 | 61.85 | 69.68 | 76.19 | 84.05 | 91.21 | 85.85 | 80.34 | 71.23 | 56.89 | 47.81 | 65.27 | |||||||||||||
| MIN | 22.16 | 36.82 | 41.85 | 46.31 | 55.10 | 67.22 | 74.55 | 72.02 | 65.98 | 53.57 | 41.53 | 35.30 | 56.28 | |||||||||||||
| YRS | 91 | 90 | 91 | 92 | 89 | 93 | 89 | 93 | 89 | 92 | 90 | 88 | 71 | |||||||||||||