| 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 | 33.91 | n | 22.16 | 22.16 | k | |
| 1925 | 22.71 | 24.89 | 28.42 | e | 32.55 | 41.00 | a | 50.05 | b | 55.25 | a | 50.40 | b | 44.72 | 40.00 | 30.28 | 25.87 | 37.18 | ||||||||
| 1926 | 21.44 | 26.52 | 32.65 | 36.27 | 41.85 | 52.18 | 55.32 | 58.08 | 51.17 | c | 44.90 | 39.80 | b | 25.15 | 40.44 | |||||||||||
| 1927 | 28.79 | 28.46 | 34.90 | 40.30 | 46.84 | 57.30 | 64.55 | 60.97 | 52.13 | 48.74 | 42.03 | 33.71 | 44.89 | |||||||||||||
| 1928 | 39.26 | 32.24 | 35.42 | 36.73 | 51.23 | 54.53 | 61.52 | 60.53 | 56.17 | 43.08 | 33.20 | c | 25.92 | 44.15 | ||||||||||||
| 1929 | 26.33 | b | 25.36 | 34.21 | 37.02 | 49.20 | a | 54.14 | a | 65.56 | 64.87 | 54.87 | 48.13 | a | 40.38 | 38.00 | a | 44.84 | ||||||||
| 1930 | 25.27 | 32.98 | 32.24 | 40.25 | 40.98 | 56.50 | 62.77 | c | 58.50 | 50.37 | 41.66 | 34.57 | 29.40 | 42.12 | ||||||||||||
| 1931 | 28.57 | a | 30.27 | b | 34.87 | 42.07 | 49.94 | 54.80 | 66.66 | 62.87 | 50.12 | 45.26 | 30.36 | a | 25.94 | 43.48 | ||||||||||
| 1932 | 23.53 | a | 28.43 | 34.32 | 36.90 | 43.73 | c | 53.65 | 56.10 | 60.90 | 56.57 | a | 43.98 | b | 40.92 | 24.10 | 41.93 | |||||||||
| 1933 | 24.35 | 25.91 | 34.73 | 44.83 | 48.98 | b | 63.86 | a | 75.02 | ----- | z | ----- | z | 50.68 | 39.32 | 32.53 | 44.02 | b | ||||||||
| 1934 | 28.55 | 30.02 | 40.05 | 42.85 | 49.32 | 49.78 | 60.37 | 60.98 | 52.32 | 44.42 | 35.50 | 27.66 | 43.49 | |||||||||||||
| 1935 | 25.68 | 28.04 | 26.10 | 34.53 | 41.61 | 54.07 | 56.50 | 58.39 | 53.33 | 37.72 | a | 29.73 | 28.89 | 39.55 | ||||||||||||
| 1936 | 28.79 | 27.12 | 32.45 | 39.37 | 45.13 | 52.38 | 60.63 | 59.68 | 50.47 | a | 44.45 | a | 40.03 | a | 27.68 | a | 42.35 | |||||||||
| 1937 | 13.23 | 26.14 | 30.10 | 35.90 | a | 48.97 | 51.29 | b | 60.93 | a | 61.35 | 56.17 | 46.08 | 37.35 | 32.97 | a | 41.71 | |||||||||
| 1938 | 29.17 | a | 22.71 | 24.00 | a | 36.20 | 42.30 | a | 50.03 | a | 58.07 | c | 59.60 | 54.67 | 41.83 | e | 29.72 | 31.23 | a | 39.96 | ||||||
| 1939 | 25.89 | 21.75 | b | 32.68 | 41.48 | 45.16 | 51.05 | 60.53 | 60.77 | 52.43 | 44.03 | 40.91 | b | 36.27 | 42.75 | |||||||||||
| 1940 | 27.53 | 26.45 | 33.19 | 36.05 | 46.71 | 56.80 | 58.31 | 60.90 | 48.87 | 45.10 | 34.45 | 30.50 | 42.07 | |||||||||||||
| 1941 | 24.73 | 28.52 | 30.26 | 30.83 | 41.89 | 46.65 | 57.71 | 54.61 | 49.63 | 39.35 | 38.58 | 26.29 | 39.09 | |||||||||||||
| 1942 | 27.42 | 22.00 | 27.61 | 34.40 | 37.79 | 49.93 | 60.42 | 59.74 | 54.07 | ----- | z | 35.82 | b | 31.74 | 40.09 | a | ||||||||||
| 1943 | 27.10 | 28.75 | 32.00 | ----- | z | 43.85 | 45.60 | 58.94 | 57.95 | 58.02 | 43.58 | 39.18 | 27.44 | 42.04 | a | |||||||||||
| 1944 | 24.94 | 21.16 | a | 28.52 | 32.20 | 43.68 | 44.88 | 55.47 | 58.76 | 54.73 | 46.32 | 29.20 | 26.90 | 38.90 | ||||||||||||
| 1945 | 22.10 | 22.05 | f | 22.62 | b | 33.52 | e | ----- | z | ----- | z | 59.63 | 56.05 | 52.45 | 44.06 | 33.03 | 29.26 | b | 39.19 | c | ||||||
| 1946 | 26.33 | a | 25.04 | 28.11 | c | 38.07 | 41.23 | 52.63 | 59.18 | 59.68 | 51.88 | 38.03 | 30.24 | c | 32.48 | j | 40.95 | a | ||||||||
| 1947 | 30.05 | j | 33.18 | i | ----- | z | 35.52 | i | 46.44 | m | 45.14 | i | ----- | z | 51.81 | j | 49.08 | j | 41.36 | i | 30.92 | e | 21.46 | e | 26.19 | j |
| 1948 | 29.93 | b | 21.29 | h | 24.00 | h | 32.14 | i | 36.91 | i | 45.80 | g | 58.90 | j | 57.44 | m | 49.50 | v | 44.62 | j | 35.67 | j | 24.60 | g | 29.93 | k |
| 1949 | 11.60 | j | 21.58 | i | 23.93 | h | 38.50 | j | 39.62 | j | 51.32 | h | 58.14 | i | 55.86 | i | 53.05 | k | 39.65 | h | 39.62 | i | 25.40 | j | ----- | z |
| 1950 | 19.19 | j | 28.95 | i | 31.06 | f | 37.15 | f | 36.48 | h | 49.10 | e | 58.39 | h | 57.44 | d | 47.13 | c | 45.04 | d | ----- | z | ----- | z | 49.68 | 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 | 26.16 | 26.80 | 31.34 | 37.25 | 44.83 | 52.33 | 60.43 | 59.23 | 52.38 | 43.93 | 35.46 | 28.74 | 41.70 | |||||||||||||
| S.D. | 4.56 | 3.25 | 4.12 | 3.72 | 3.73 | 4.27 | 4.55 | 2.95 | 3.23 | 3.26 | 4.41 | 4.19 | 2.22 | |||||||||||||
| SKEW | -0.00 | -0.01 | -0.29 | 0.26 | 0.11 | 0.54 | 1.54 | -1.07 | -0.40 | -0.14 | -0.06 | 0.38 | -0.34 | |||||||||||||
| MAX | 39.26 | 32.98 | 40.05 | 44.83 | 51.23 | 63.86 | 75.02 | 64.87 | 58.02 | 50.68 | 42.03 | 38.00 | 44.89 | |||||||||||||
| MIN | 13.23 | 21.16 | 22.62 | 30.83 | 37.79 | 44.88 | 55.25 | 50.40 | 44.72 | 37.72 | 29.20 | 21.46 | 37.18 | |||||||||||||
| YRS | 23 | 21 | 22 | 21 | 21 | 22 | 22 | 22 | 22 | 22 | 23 | 23 | 17 | |||||||||||||