| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1924 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 46.12 | n | 33.90 | 33.90 | k | |
| 1925 | 32.97 | 35.79 | 39.39 | 45.47 | 52.52 | 64.63 | 77.16 | 71.81 | 61.77 | 54.71 | 42.67 | 35.81 | 51.22 | |||||||||||||
| 1926 | 33.48 | 38.61 | 47.68 | 49.07 | 54.65 | 64.77 | 67.94 | 69.94 | 62.69 | a | 55.16 | 47.48 | a | 35.71 | 52.26 | |||||||||||
| 1927 | 39.71 | 39.57 | 48.19 | 54.27 | 59.74 | 69.80 | 76.97 | 72.13 | 62.93 | 58.84 | 51.33 | 43.29 | 56.40 | |||||||||||||
| 1928 | 50.71 | 45.52 | 46.32 | 48.00 | 64.26 | 67.47 | 74.52 | 71.55 | 66.67 | 53.19 | 41.89 | c | 35.90 | 55.50 | ||||||||||||
| 1929 | 37.10 | a | 38.64 | 47.32 | 49.37 | 62.10 | a | 66.66 | a | 77.23 | 75.61 | 65.67 | 57.23 | 49.97 | 45.60 | a | 56.04 | |||||||||
| 1930 | 35.16 | 44.11 | 47.13 | 52.87 | 54.97 | 70.27 | 75.61 | c | 69.16 | 60.37 | 51.84 | 43.77 | 37.97 | 53.60 | ||||||||||||
| 1931 | 40.55 | 44.75 | 48.48 | 55.07 | 63.06 | 66.67 | 79.03 | 74.48 | 61.47 | 56.48 | 40.20 | 35.74 | 55.50 | |||||||||||||
| 1932 | 36.29 | 43.10 | 49.19 | 51.03 | 57.43 | c | 68.70 | 73.68 | 74.90 | 69.66 | a | 55.53 | a | 50.57 | 36.13 | 55.52 | ||||||||||
| 1933 | 36.06 | 39.82 | 47.65 | 60.07 | 62.38 | b | 76.45 | a | 87.29 | ----- | z | ----- | z | 63.58 | 52.37 | 42.06 | 56.77 | b | ||||||||
| 1934 | 42.10 | 41.04 | 53.87 | 56.40 | 61.81 | 63.10 | 71.74 | 73.03 | 64.43 | 54.23 | 44.43 | 36.87 | 55.25 | |||||||||||||
| 1935 | 36.74 | 40.93 | 39.06 | 47.00 | 56.10 | 67.90 | 69.00 | 71.00 | 65.13 | 47.57 | a | 39.50 | 38.39 | 51.53 | ||||||||||||
| 1936 | 39.16 | 37.52 | 47.45 | 54.37 | 58.97 | 64.53 | 72.97 | 71.42 | 63.76 | a | 56.32 | 51.10 | 36.33 | a | 54.49 | |||||||||||
| 1937 | 23.23 | 36.64 | 41.94 | 50.90 | a | 66.06 | 61.79 | b | 71.40 | a | 71.23 | 67.20 | 58.39 | 46.30 | 43.35 | 53.20 | ||||||||||
| 1938 | 39.61 | 32.07 | 34.87 | a | 49.20 | 56.53 | a | 62.14 | a | 69.45 | b | 70.39 | 65.80 | 51.89 | d | 42.40 | 41.20 | a | 51.30 | |||||||
| 1939 | 36.55 | 35.44 | a | 46.32 | 54.67 | 56.55 | 61.83 | 71.19 | 71.32 | 63.80 | 56.16 | 52.31 | a | 44.23 | 54.20 | |||||||||||
| 1940 | 37.58 | 36.62 | 46.42 | 48.50 | 57.71 | 68.30 | 67.52 | 71.35 | 57.73 | 55.39 | 44.43 | 38.74 | 52.52 | |||||||||||||
| 1941 | 34.13 | 39.11 | 45.23 | 43.63 | 51.84 | 56.13 | 67.90 | 64.13 | 62.10 | 49.77 | 49.30 | 33.71 | 49.75 | |||||||||||||
| 1942 | 38.52 | 33.21 | 42.58 | 47.53 | 50.06 | 61.07 | 70.97 | 70.58 | 67.60 | ----- | z | 46.28 | a | 41.42 | 51.80 | a | ||||||||||
| 1943 | 36.58 | 42.14 | 44.45 | ----- | z | 55.68 | 55.53 | 70.77 | 68.77 | 71.70 | 52.77 | 49.10 | 37.71 | 53.20 | a | |||||||||||
| 1944 | 37.26 | 33.36 | a | 43.10 | 45.40 | 56.45 | 55.03 | 68.03 | 71.48 | 69.67 | 59.94 | 38.73 | 38.32 | 51.40 | ||||||||||||
| 1945 | 34.52 | 33.52 | c | 33.60 | a | 44.52 | c | ----- | z | ----- | z | 70.29 | 66.23 | 62.30 | 51.16 | 40.20 | 38.17 | a | 47.45 | b | ||||||
| 1946 | 39.03 | 37.00 | 38.14 | b | 49.73 | 50.39 | 72.13 | 79.23 | 77.45 | 68.90 | 54.42 | 48.22 | c | 53.23 | i | 55.88 | a | |||||||||
| 1947 | 55.05 | j | 47.11 | i | ----- | z | 47.82 | h | 58.61 | m | 53.62 | i | 62.27 | i | 62.10 | j | 60.60 | j | 50.45 | i | 41.68 | e | 33.07 | c | 37.38 | j |
| 1948 | 43.27 | a | 33.71 | h | 36.61 | h | 40.38 | i | 47.18 | i | 54.96 | g | 69.29 | j | 68.33 | m | 60.38 | v | 54.57 | j | 45.10 | j | 33.75 | g | 43.27 | k |
| 1949 | 25.29 | j | 33.42 | i | 34.57 | h | 52.15 | j | 51.19 | j | 62.59 | h | 69.55 | i | 67.14 | i | 64.16 | k | 50.87 | h | 50.95 | i | 36.05 | j | ----- | z |
| 1950 | 28.90 | j | 43.84 | i | 42.64 | f | 50.62 | f | 48.96 | h | 61.52 | e | 69.87 | h | 70.33 | d | 58.00 | c | 54.26 | d | ----- | z | ----- | z | 61.03 | h |
| 1951 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1952 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1953 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1954 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1955 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1956 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1957 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1958 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1959 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1960 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1961 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1962 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1963 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1964 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1965 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1966 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1967 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1968 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1969 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1970 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1971 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1972 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1973 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1974 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1975 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1976 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1977 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1978 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1979 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1980 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1981 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1982 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1983 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1984 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1985 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1986 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1987 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1988 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1989 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1990 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1991 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1992 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1993 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 1994 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 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 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 2006 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 2007 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 2008 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 2009 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 2010 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 37.40 | 38.57 | 44.47 | 50.34 | 57.58 | 64.84 | 73.18 | 71.29 | 64.52 | 54.95 | 45.84 | 38.42 | 53.51 | |||||||||||||
| S.D. | 4.89 | 3.89 | 4.95 | 4.30 | 4.51 | 5.37 | 4.87 | 2.89 | 3.71 | 3.53 | 4.42 | 3.54 | 2.04 | |||||||||||||
| SKEW | -0.14 | 0.12 | -0.62 | 0.42 | 0.11 | -0.06 | 1.11 | -0.25 | 0.04 | 0.24 | -0.03 | 0.47 | -0.19 | |||||||||||||
| MAX | 50.71 | 45.52 | 53.87 | 60.07 | 66.06 | 76.45 | 87.29 | 77.45 | 71.70 | 63.58 | 52.37 | 45.60 | 56.40 | |||||||||||||
| MIN | 23.23 | 32.07 | 33.60 | 43.63 | 50.06 | 55.03 | 67.52 | 64.13 | 57.73 | 47.57 | 38.73 | 33.07 | 49.75 | |||||||||||||
| YRS | 23 | 22 | 22 | 21 | 21 | 22 | 22 | 22 | 22 | 22 | 23 | 23 | 17 | |||||||||||||