| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1923 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1924 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1925 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1926 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1927 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 52.98 | a | ----- | z | ----- | z | 52.98 | k |
| 1928 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1929 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1930 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1931 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1932 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1933 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1934 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1935 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1936 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1937 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1938 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1939 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1940 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1941 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1942 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1943 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1944 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1945 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1946 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1947 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1948 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1949 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1950 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1951 | ----- | z | ----- | z | ----- | z | 50.02 | d | 56.11 | 62.02 | 72.97 | 69.58 | 61.20 | 49.68 | 34.28 | 23.87 | 53.30 | c | ||||||||
| 1952 | 27.76 | 27.84 | 33.94 | 48.03 | 58.18 | 65.32 | 71.15 | 71.94 | 63.95 | 53.53 | 34.00 | 30.42 | 48.84 | |||||||||||||
| 1953 | 36.42 | 30.07 | 41.81 | 45.27 | 50.17 | d | 64.88 | 73.45 | 70.90 | 63.88 | 50.02 | 42.23 | 21.37 | 49.21 | ||||||||||||
| 1954 | 29.90 | 34.73 | 38.66 | 53.10 | 60.90 | a | 64.73 | 75.40 | 70.44 | 64.53 | 53.25 | a | 41.52 | 29.82 | 51.42 | |||||||||||
| 1955 | 20.63 | a | 20.34 | 36.82 | 46.47 | 55.15 | 63.88 | 72.68 | 72.63 | 62.98 | 52.27 | 36.67 | 34.84 | 47.95 | ||||||||||||
| 1956 | 36.87 | 26.72 | 41.48 | 48.90 | 58.58 | a | 68.33 | 71.90 | 68.27 | 64.10 | 51.58 | 31.87 | 28.37 | 49.75 | ||||||||||||
| 1957 | 27.21 | 36.57 | 43.08 | a | 47.92 | e | 54.19 | 65.13 | 72.71 | 71.77 | 60.17 | 50.11 | 33.57 | 33.56 | 49.67 | |||||||||||
| 1958 | 29.73 | a | 38.96 | b | 37.97 | b | 44.83 | 61.42 | a | 68.22 | a | 71.66 | 72.74 | 63.47 | 52.60 | 39.07 | a | 34.24 | 51.24 | |||||||
| 1959 | 32.05 | 33.78 | a | 40.68 | a | 50.37 | 54.85 | 70.00 | 74.56 | 71.87 | 60.23 | 50.27 | 37.05 | 29.91 | b | 50.47 | ||||||||||
| 1960 | 26.42 | a | 28.78 | 41.35 | 49.90 | 57.00 | 67.42 | 73.56 | 68.87 | 62.67 | 47.68 | 38.30 | 26.60 | 49.05 | ||||||||||||
| 1961 | 25.66 | 34.69 | a | 37.15 | a | 45.18 | 55.73 | 68.30 | 74.22 | a | 72.27 | 57.68 | 47.53 | 32.40 | a | 26.95 | a | 48.15 | ||||||||
| 1962 | 20.63 | a | 33.23 | 33.84 | 50.29 | a | 54.60 | 64.12 | 71.06 | 69.47 | 63.37 | 53.32 | a | 41.90 | 28.94 | 48.73 | ||||||||||
| 1963 | 20.60 | 38.68 | 38.48 | 45.10 | a | 61.05 | 63.02 | a | 74.66 | 72.95 | 65.92 | 56.37 | 40.95 | 25.73 | a | 50.29 | ||||||||||
| 1964 | 24.55 | 26.93 | 31.55 | 46.98 | 56.11 | 64.58 | 75.64 | b | 70.76 | 61.25 | 54.29 | 33.21 | a | 33.29 | 48.26 | |||||||||||
| 1965 | 34.13 | 32.91 | 38.33 | a | 49.10 | a | 53.05 | 61.41 | a | 71.33 | a | 69.11 | 56.98 | 53.92 | 43.93 | 33.29 | b | 49.79 | ||||||||
| 1966 | 28.50 | 30.89 | 43.26 | 48.93 | 61.32 | 67.47 | 75.81 | 72.06 | 64.37 | 49.27 | 42.50 | 27.66 | 51.00 | |||||||||||||
| 1967 | 27.50 | 34.77 | 44.92 | 45.03 | 54.73 | a | 62.10 | a | 74.50 | 73.68 | 63.50 | 51.40 | 40.85 | 20.03 | 49.42 | |||||||||||
| 1968 | 22.71 | 37.72 | 42.35 | 43.82 | 54.79 | 67.37 | 73.10 | 65.74 | 59.13 | 51.32 | 38.08 | 27.80 | a | 48.66 | ||||||||||||
| 1969 | 35.35 | 34.34 | 37.56 | 49.37 | 62.63 | 62.70 | 74.31 | 75.65 | 64.88 | 44.40 | 36.73 | 32.05 | 50.83 | |||||||||||||
| 1970 | 30.92 | 39.11 | 38.69 | 43.25 | 57.82 | 64.90 | 73.53 | 72.82 | 59.35 | 45.84 | 41.12 | 30.77 | 49.84 | |||||||||||||
| 1971 | 30.00 | a | 30.88 | 39.05 | 47.27 | 55.02 | 66.95 | 75.42 | 73.05 | 59.33 | 46.44 | 36.73 | 24.32 | 48.70 | ||||||||||||
| 1972 | 29.68 | 38.02 | 46.03 | 48.85 | 57.92 | a | 67.20 | 74.53 | 69.48 | 60.92 | 50.19 | 35.82 | 22.66 | 50.11 | ||||||||||||
| 1973 | 20.77 | 33.34 | 37.50 | a | 43.65 | 57.79 | 66.03 | 72.61 | 71.73 | 58.78 | 50.47 | 37.90 | 32.56 | 48.60 | ||||||||||||
| 1974 | 23.26 | 25.59 | 43.92 | 46.00 | 59.85 | 69.25 | 73.82 | 70.00 | 62.45 | 50.60 | a | 38.45 | 25.06 | 49.02 | ||||||||||||
| 1975 | 23.02 | 30.48 | 39.08 | 41.60 | 52.81 | 62.67 | 74.66 | 70.95 | 62.03 | 50.23 | 35.30 | 28.79 | 47.63 | |||||||||||||
| 1976 | 23.98 | 36.72 | 33.79 | b | 47.70 | 60.50 | 65.77 | 74.89 | 69.77 | 63.18 | 47.77 | 37.60 | 27.53 | 49.10 | ||||||||||||
| 1977 | 23.50 | 33.05 | 36.42 | 52.23 | 54.70 | a | 72.12 | a | 75.53 | 73.61 | 65.13 | 53.55 | 41.23 | 35.13 | 51.35 | |||||||||||
| 1978 | 31.00 | 35.52 | b | 46.48 | 49.27 | 54.76 | 66.58 | 74.63 | 70.50 | 61.90 | 53.35 | 37.98 | 25.42 | 50.62 | ||||||||||||
| 1979 | 22.71 | 30.04 | 39.54 | g | 47.08 | 57.06 | 65.62 | 72.76 | 70.26 | 66.63 | 54.39 | 31.20 | 30.21 | 49.81 | a | |||||||||||
| 1980 | 32.50 | 36.48 | 38.90 | 47.82 | 53.15 | 64.81 | a | 73.19 | 69.77 | 61.25 | 48.35 | 38.80 | 35.10 | 50.01 | ||||||||||||
| 1981 | 32.47 | 35.20 | 40.84 | 51.75 | 55.21 | 68.12 | 74.29 | 71.11 | 64.75 | 48.16 | 41.85 | 32.77 | 51.38 | |||||||||||||
| 1982 | 21.32 | 28.39 | 39.81 | 45.68 | 54.45 | 62.80 | 70.35 | a | 71.66 | 61.15 | 45.63 | 34.68 | 26.13 | a | 46.84 | |||||||||||
| 1983 | 31.27 | 36.07 | 41.30 | a | 43.07 | a | 52.25 | a | 64.19 | a | 70.70 | a | 70.95 | 63.68 | 51.21 | 39.67 | a | 30.37 | 49.56 | |||||||
| 1984 | 19.66 | 25.33 | 37.88 | a | 45.43 | a | 58.89 | 63.02 | 70.92 | a | 70.45 | 62.43 | a | 44.79 | 37.62 | b | 27.34 | 46.98 | ||||||||
| 1985 | 25.66 | 27.07 | 39.00 | 49.73 | 57.92 | 66.64 | a | 72.29 | 69.65 | a | 58.27 | 49.37 | 34.83 | 24.95 | 47.95 | |||||||||||
| 1986 | 32.95 | 37.98 | 45.23 | 47.38 | a | 55.58 | 68.33 | a | 70.27 | 71.24 | 56.90 | 48.19 | 38.15 | 29.89 | 50.17 | |||||||||||
| 1987 | 23.68 | 33.98 | a | 38.56 | 51.48 | 57.35 | 66.77 | 69.45 | 68.05 | 59.40 | 51.92 | 37.73 | 26.60 | 48.75 | ||||||||||||
| 1988 | 18.60 | b | 27.45 | 38.43 | a | 49.60 | 55.08 | 69.50 | 72.89 | 69.90 | 59.57 | 54.56 | 37.53 | 23.74 | 48.07 | |||||||||||
| 1989 | 13.45 | 24.36 | 45.21 | 51.88 | 56.35 | 64.00 | 73.39 | 68.90 | 61.22 | 49.21 | 36.98 | 27.47 | 47.70 | |||||||||||||
| 1990 | 30.16 | 27.54 | ----- | z | 51.34 | a | 56.71 | 68.02 | a | 72.89 | 69.08 | 65.47 | 50.68 | 37.20 | 18.24 | 49.76 | a | |||||||||
| 1991 | 19.65 | 34.30 | 40.11 | 45.27 | 52.54 | h | 64.70 | 71.85 | 71.13 | 60.28 | 49.44 | 36.93 | 29.48 | 47.56 | a | |||||||||||
| 1992 | ----- | z | 37.40 | 43.89 | 54.18 | 59.73 | 65.03 | 68.82 | 70.18 | 62.12 | 52.79 | 33.30 | 22.84 | 51.84 | a | |||||||||||
| 1993 | 27.23 | 30.30 | 41.92 | 48.03 | 58.82 | 61.73 | 67.58 | 68.40 | 59.45 | 48.44 | 32.37 | 28.03 | a | 47.69 | ||||||||||||
| 1994 | 31.37 | 32.95 | 43.15 | 49.53 | 59.53 | 67.74 | a | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 47.38 | f | |||||
| 1995 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1996 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1997 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1998 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1999 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 2000 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 2001 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 2002 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 2003 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 2004 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 2005 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 69.44 | v | 60.26 | a | 50.34 | 39.58 | e | 27.38 | n | 50.06 | i | |
| 2006 | 28.88 | o | 30.83 | m | 39.54 | s | 48.86 | s | ----- | z | 65.42 | j | 73.63 | d | 68.82 | 56.76 | e | 50.07 | d | 39.85 | 24.83 | a | 52.33 | f | ||
| 2007 | 17.93 | b | 36.11 | e | 44.23 | 49.81 | d | 58.87 | h | 68.37 | c | 75.73 | g | 74.00 | 63.34 | a | 51.00 | 41.87 | 24.52 | b | 47.12 | b | ||||
| 2008 | 25.17 | b | 30.59 | 40.17 | a | 46.59 | a | 53.48 | d | 66.15 | 74.27 | 72.03 | 62.10 | 51.63 | a | 40.93 | b | 27.81 | 49.24 | |||||||
| 2009 | 28.07 | a | 35.27 | 44.31 | 47.86 | a | 59.81 | 63.50 | 73.37 | 69.38 | a | 66.22 | e | 47.92 | a | 39.15 | 20.41 | b | 49.61 | |||||||
| 2010 | 25.83 | b | 31.84 | 41.60 | a | 46.72 | a | 52.72 | b | 66.23 | 73.68 | 71.05 | c | 63.96 | e | 50.87 | 36.65 | d | 35.65 | a | 49.73 | |||||
| 2011 | 22.19 | e | 30.46 | 43.70 | i | 45.98 | 51.90 | a | 64.23 | 71.74 | 73.50 | t | ----- | z | ----- | z | ----- | z | ----- | z | 47.75 | f | ||||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 26.48 | 32.37 | 40.19 | 47.85 | 56.55 | 65.75 | 72.97 | 70.81 | 61.89 | 50.46 | 37.72 | 28.07 | 49.30 | |||||||||||||
| S.D. | 5.33 | 4.39 | 3.46 | 2.79 | 2.90 | 2.41 | 1.85 | 1.83 | 2.55 | 2.67 | 3.13 | 4.27 | 1.21 | |||||||||||||
| SKEW | -0.07 | -0.50 | -0.26 | 0.02 | 0.12 | 0.23 | -0.76 | 0.07 | -0.21 | -0.22 | -0.19 | -0.12 | -0.02 | |||||||||||||
| MAX | 36.87 | 39.11 | 46.48 | 54.18 | 62.63 | 72.12 | 75.81 | 75.65 | 66.63 | 56.37 | 43.93 | 35.65 | 51.42 | |||||||||||||
| MIN | 13.45 | 20.34 | 31.55 | 41.60 | 50.17 | 61.41 | 67.58 | 65.74 | 56.76 | 44.40 | 31.20 | 18.24 | 46.84 | |||||||||||||
| YRS | 47 | 48 | 45 | 49 | 47 | 49 | 48 | 48 | 49 | 50 | 49 | 48 | 41 | |||||||||||||