| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1915 | 0.05 | a | 0.02 | 0.48 | 0.38 | 2.29 | 2.11 | 1.14 | 1.07 | 2.86 | 0.02 | 0.40 | a | 0.52 | 11.34 | |||||||||||
| 1916 | 0.11 | 0.32 | 0.09 | 0.45 | 1.48 | 1.64 | 0.47 | 0.56 | 0.19 | 1.39 | 0.27 | 0.21 | 7.18 | |||||||||||||
| 1917 | 0.40 | 0.25 | 0.26 | 1.72 | 1.64 | 0.27 | 0.82 | 0.92 | 0.83 | 0.24 | 0.59 | 1.05 | 8.99 | |||||||||||||
| 1918 | 0.76 | 0.18 | 0.91 | 1.69 | 0.70 | 1.49 | 1.31 | 0.26 | 2.24 | 0.46 | 1.81 | 0.00 | 11.81 | |||||||||||||
| 1919 | 0.02 | 0.17 | 0.02 | 1.20 | 0.02 | 0.34 | 0.36 | 0.42 | 0.69 | 1.31 | 0.33 | 0.59 | 5.47 | |||||||||||||
| 1920 | 0.09 | 0.17 | 0.10 | 0.95 | 0.79 | 1.58 | 1.16 | 0.59 | 0.00 | 0.28 | 0.24 | 0.10 | 6.05 | |||||||||||||
| 1921 | 0.10 | 0.04 | 0.48 | 0.64 | 2.95 | 1.23 | 1.53 | 0.61 | 0.30 | 0.04 | 1.61 | 0.76 | 10.29 | |||||||||||||
| 1922 | 0.46 | 0.20 | 0.21 | 1.79 | 0.74 | 1.18 | 1.70 | 1.00 | 0.20 | 0.89 | 0.94 | 1.02 | 10.33 | |||||||||||||
| 1923 | 0.00 | 0.27 | 0.51 | 1.08 | 0.70 | 1.69 | 1.85 | 1.64 | 3.27 | 2.14 | 0.34 | 0.71 | 14.20 | |||||||||||||
| 1924 | 0.41 | 0.55 | 1.31 | 0.55 | 0.66 | 1.47 | 0.94 | 0.07 | 2.16 | 2.20 | 0.47 | 0.60 | 11.39 | |||||||||||||
| 1925 | 0.13 | 0.13 | 0.58 | 2.41 | 2.06 | 1.87 | 0.58 | 0.12 | 1.11 | 2.22 | 0.27 | 0.71 | 12.19 | |||||||||||||
| 1926 | 0.26 | 0.13 | 0.60 | 2.53 | 2.54 | 1.13 | 0.86 | 0.94 | 1.62 | 0.39 | 1.10 | 0.24 | 12.34 | |||||||||||||
| 1927 | 0.36 | 0.45 | 0.07 | 1.18 | 1.42 | 1.91 | 0.89 | 2.16 | 1.33 | 0.22 | 0.97 | 0.27 | 11.23 | |||||||||||||
| 1928 | 0.20 | a | 0.28 | 0.28 | 0.11 | 1.58 | 2.93 | 2.70 | 0.29 | 0.08 | 0.47 | 0.58 | 0.18 | 9.68 | ||||||||||||
| 1929 | 0.48 | 0.40 | 0.96 | 1.08 | 1.08 | 0.84 | 0.70 | 0.17 | 0.97 | 0.12 | 0.65 | 0.27 | 7.72 | |||||||||||||
| 1930 | 0.30 | 0.16 | 0.19 | 0.51 | 0.77 | 0.80 | 0.99 | 1.66 | 1.15 | 2.15 | 0.05 | 0.02 | 8.75 | |||||||||||||
| 1931 | 0.00 | 0.03 | 0.61 | 1.12 | 1.33 | 1.01 | 0.36 | 1.11 | 1.65 | 0.56 | 0.32 | 0.05 | 8.15 | |||||||||||||
| 1932 | 0.21 | 0.12 | 0.37 | 1.10 | 3.01 | 3.51 | 1.04 | 0.13 | 0.86 | 1.18 | 0.36 | 0.15 | 12.04 | |||||||||||||
| 1933 | 0.27 | 0.45 | 0.38 | 1.90 | 2.20 | 0.07 | 0.37 | 2.17 | 0.15 | 0.25 | 0.25 | 0.41 | 8.87 | |||||||||||||
| 1934 | 0.00 | 0.08 | 0.29 | 0.97 | 0.20 | 2.44 | 0.93 | 0.30 | 0.60 | 0.00 | 0.10 | 0.12 | 6.03 | |||||||||||||
| 1935 | 0.02 | b | 0.12 | 0.62 | 1.10 | 1.51 | 0.94 | 0.02 | 1.29 | 0.11 | 0.20 | 0.28 | 0.04 | 6.25 | ||||||||||||
| 1936 | 0.39 | 0.99 | 1.08 | 0.73 | 0.10 | 1.36 | 1.90 | 0.95 | 0.44 | 0.44 | 0.07 | 0.14 | 8.59 | |||||||||||||
| 1937 | 0.05 | 0.42 | 0.37 | 0.40 | 1.31 | 1.61 | 0.47 | 0.00 | 0.92 | 0.85 | 0.26 | 0.27 | 6.93 | |||||||||||||
| 1938 | 0.53 | 0.06 | 0.95 | 0.53 | 3.42 | 1.33 | 2.00 | 0.11 | 0.26 | 0.68 | 1.04 | 0.11 | 11.02 | |||||||||||||
| 1939 | 0.21 | 0.22 | 0.53 | 1.09 | 1.99 | 2.24 | 0.60 | 0.67 | 0.78 | 0.58 | 0.00 | 0.15 | 9.06 | |||||||||||||
| 1940 | 0.57 | 0.23 | 0.32 | 1.40 | 0.73 | 1.63 | 1.47 | 0.10 | 1.69 | 0.90 | 0.47 | 0.04 | 9.55 | |||||||||||||
| 1941 | 0.17 | 0.17 | 0.45 | 2.23 | 1.22 | 3.06 | 2.25 | 1.74 | 2.44 | 0.43 | 0.36 | 0.17 | 14.69 | |||||||||||||
| 1942 | 0.30 | 0.13 | 0.29 | 0.65 | 2.04 | 0.94 | 0.86 | 0.26 | 1.13 | 1.98 | 0.72 | 0.25 | 9.55 | |||||||||||||
| 1943 | 0.88 | 0.47 | 0.68 | 1.07 | 1.07 | 1.56 | 0.39 | 0.39 | 0.22 | 1.08 | 0.61 | 0.74 | 9.16 | |||||||||||||
| 1944 | 0.33 | 0.34 | 0.99 | 1.96 | 2.40 | 3.89 | 1.67 | 0.40 | 0.95 | 0.27 | 0.64 | 0.59 | 14.43 | |||||||||||||
| 1945 | 0.25 | 0.59 | 1.02 | 0.85 | 1.63 | 4.07 | 1.83 | 1.62 | 1.08 | 0.62 | 0.37 | 0.69 | 14.62 | |||||||||||||
| 1946 | 0.63 | a | 0.21 | 1.70 | 0.02 | 1.75 | 0.66 | 1.01 | 0.88 | 1.19 | 1.57 | 0.38 | 0.58 | 10.58 | ||||||||||||
| 1947 | 0.09 | 0.68 | 0.77 | 0.87 | 1.03 | 1.39 | 1.35 | 0.24 | 0.68 | 0.28 | 0.93 | 0.22 | 8.53 | |||||||||||||
| 1948 | 0.85 | 0.55 | 0.38 | 1.36 | 0.85 | 2.41 | 0.74 | 0.43 | 0.90 | 0.10 | 0.52 | 0.55 | 9.64 | |||||||||||||
| 1949 | 0.49 | 0.11 | 0.44 | 0.23 | 1.70 | 1.82 | 0.50 | 0.44 | 0.57 | 1.18 | 0.00 | a | 0.25 | 7.73 | ||||||||||||
| 1950 | 0.55 | b | 0.13 | a | 0.17 | 2.04 | 0.82 | 0.97 | 1.01 | 0.24 | 2.41 | a | 0.08 | 1.19 | 0.28 | 9.89 | ||||||||||
| 1951 | 0.77 | 0.09 | 0.58 | 1.02 | 0.90 | 0.72 | 2.54 | 1.86 | 0.84 | 1.14 | 0.39 | 0.31 | 11.16 | |||||||||||||
| 1952 | 0.20 | 0.35 | 0.51 | 0.59 | 2.92 | 0.86 | 0.57 | 1.27 | a | 0.16 | a | 0.03 | 0.21 | 0.02 | 7.69 | |||||||||||
| 1953 | 0.14 | 0.97 | 0.18 | 2.80 | 1.27 | 0.97 | 0.02 | 0.56 | 0.71 | 0.43 | 0.57 | 0.27 | 8.89 | |||||||||||||
| 1954 | 1.06 | 0.56 | 1.63 | 1.19 | 0.34 | 0.97 | 0.76 | 0.42 | 0.51 | 0.30 | 0.05 | 0.13 | 7.92 | |||||||||||||
| 1955 | 0.00 | 1.38 | 1.18 | 0.59 | 1.97 | 2.23 | 0.58 | 0.18 | 0.74 | 0.30 | 0.57 | 0.48 | 10.20 | |||||||||||||
| 1956 | 0.08 | 0.09 | 0.59 | 0.61 | 0.68 | 0.27 | 0.45 | 0.22 | 0.15 | 0.00 | 0.44 | 0.00 | 3.58 | |||||||||||||
| 1957 | 0.04 | 0.44 | 0.02 | 2.03 | 3.84 | 2.00 | 0.54 | 0.73 | 0.83 | 1.30 | 0.37 | 0.03 | 12.17 | |||||||||||||
| 1958 | 0.11 | 0.30 | 0.40 | 0.66 | 1.54 | 3.52 | 2.66 | 0.90 | 0.31 | 0.11 | 0.58 | 0.05 | 11.14 | |||||||||||||
| 1959 | 0.09 | 0.18 | 0.30 | 0.52 | 0.22 | 1.66 | 0.41 | 0.52 | 0.30 | 0.89 | 0.96 | 0.19 | 6.24 | |||||||||||||
| 1960 | 0.00 | 0.33 | 0.32 | 0.63 | 0.46 | 1.67 | 0.38 | 0.87 | 0.16 | 0.44 | 0.72 | 0.16 | 6.14 | |||||||||||||
| 1961 | 0.04 | 0.13 | 0.37 | 0.46 | 1.70 | 0.81 | 1.14 | 0.41 | 3.36 | 1.04 | 0.55 | 0.38 | 10.39 | |||||||||||||
| 1962 | 0.95 | 0.40 | 0.47 | 0.56 | 2.26 | 2.32 | 2.01 | 1.71 | 1.07 | 0.00 | z | 0.40 | 0.02 | 12.17 | ||||||||||||
| 1963 | 0.21 | 0.29 | 0.05 | 2.12 | 1.30 | 2.25 | 0.60 | 0.22 | 1.37 | 0.11 | 0.04 | 0.07 | 8.63 | |||||||||||||
| 1964 | 0.04 | 0.09 | 0.15 | 1.09 | 1.85 | 2.40 | 0.19 | 0.04 | 0.01 | 1.07 | 0.33 | 1.17 | 8.43 | |||||||||||||
| 1965 | 0.23 | 0.15 | 0.56 | 0.42 | 2.24 | 2.56 | 0.47 | 1.34 | 0.79 | 0.09 | 0.00 | 0.04 | 8.89 | |||||||||||||
| 1966 | 0.02 | 0.18 | 0.14 | 1.22 | 0.24 | 1.09 | 0.66 | 0.70 | 1.90 | 0.05 | 0.55 | 0.07 | 6.82 | |||||||||||||
| 1967 | 0.30 | 0.21 | 0.70 | 0.29 | 2.50 | 3.52 | 0.93 | 0.44 | 0.43 | 0.66 | 0.19 | 0.44 | 10.61 | |||||||||||||
| 1968 | 0.19 | 0.15 | 0.45 | 0.09 | 1.73 | 2.65 | 0.73 | 2.58 | 0.54 | m | 0.00 | z | 0.00 | z | 0.00 | z | 8.57 | |||||||||
| 1969 | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | |
| 1970 | 0.19 | 0.00 | 0.71 | 1.26 | 1.54 | 1.02 | 0.57 | 0.02 | 2.74 | 0.43 | 0.58 | 0.16 | 9.22 | |||||||||||||
| 1971 | 0.21 | 0.17 | 0.61 | 1.98 | 2.11 | 0.57 | 0.31 | 0.50 | 0.80 | 2.75 | 0.68 | 0.28 | 10.97 | |||||||||||||
| 1972 | 1.92 | 0.11 | 0.28 | 0.25 | 1.70 | 1.28 | 0.43 | 2.47 | 0.51 | 0.71 | 0.25 | 0.65 | 10.56 | |||||||||||||
| 1973 | 0.00 | 0.03 | 0.23 | 1.07 | 0.17 | 1.41 | 3.27 | 0.16 | 2.39 | 0.31 | 0.76 | 0.25 | 10.05 | |||||||||||||
| 1974 | 0.23 | 0.05 | 0.60 | 1.06 | 1.27 | 1.75 | 0.95 | 0.65 | 0.25 | 1.69 | 0.38 | 0.10 | 8.98 | |||||||||||||
| 1975 | 1.91 | 0.16 | 0.36 | 0.90 | 2.63 | 1.77 | 1.41 | 0.62 | 0.26 | 1.87 | 0.21 | 0.27 | 12.37 | |||||||||||||
| 1976 | 0.49 | 0.10 | 0.67 | 1.52 | 0.08 | 2.98 | 0.18 | 0.71 | 1.72 | 0.24 | 0.03 | 0.10 | 8.82 | |||||||||||||
| 1977 | 0.38 | 0.02 | 0.35 | 0.37 | 2.69 | 0.89 | 0.21 | 0.87 | 0.72 | 0.25 | 0.25 | 0.85 | 7.85 | |||||||||||||
| 1978 | 0.21 | 1.18 | 0.00 | 2.29 | 4.73 | 0.10 | 1.67 | 0.23 | 1.57 | 0.30 | 0.97 | 0.87 | 14.12 | |||||||||||||
| 1979 | 0.62 | 0.17 | 0.62 | 0.51 | 1.31 | 0.62 | 0.24 | 1.63 | 0.12 | 0.48 | 0.22 | 0.05 | 6.59 | |||||||||||||
| 1980 | 0.99 | 0.18 | 1.06 | 0.18 | 3.19 | 0.84 | 0.97 | 1.06 | 1.95 | 0.42 | 0.41 | 0.00 | 11.25 | |||||||||||||
| 1981 | 0.04 | 0.53 | 0.42 | 0.59 | 4.00 | 0.69 | 1.23 | 0.29 | 0.38 | 0.68 | 0.09 | 0.40 | 9.34 | |||||||||||||
| 1982 | 0.23 | b | 0.01 | 0.30 | 0.00 | z | 2.00 | 3.35 | 2.33 | 1.33 | 2.74 | 1.12 | 0.17 | 0.07 | 13.65 | |||||||||||
| 1983 | 0.02 | 0.15 | 0.61 | c | 0.92 | 0.91 | 1.31 | 0.83 | 0.65 | 0.91 | 0.85 | 0.57 | 0.41 | 8.14 | ||||||||||||
| 1984 | 0.24 | 0.05 | 0.00 | 1.13 | 1.65 | 0.80 | 1.04 | 0.65 | 0.89 | 0.36 | 0.04 | 0.22 | 7.07 | |||||||||||||
| 1985 | 0.22 | 0.04 | 0.38 | 0.09 | 1.09 | 1.23 | 0.69 | 0.50 | 0.61 | 0.26 | 0.72 | 0.00 | 5.83 | |||||||||||||
| 1986 | 0.05 | 0.65 | 0.49 | 1.03 | 0.52 | 1.83 | 0.50 | 0.24 | 1.68 | 0.00 | z | 0.00 | z | 0.00 | z | 6.99 | ||||||||||
| 1987 | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 2.46 | 2.77 | 0.73 | 0.74 | 0.15 | 0.42 | 0.13 | 7.40 | ||||||||
| 1988 | 0.00 | 0.50 | 0.26 | 0.68 | 1.85 | 0.44 | 0.61 | 1.24 | 0.78 | 0.40 | 0.53 | 0.27 | 7.56 | |||||||||||||
| 1989 | 0.29 | 0.50 | 0.75 | 1.03 | 2.93 | 0.92 | 1.76 | 1.09 | 0.77 | 0.77 | 0.83 | 0.44 | 12.08 | |||||||||||||
| 1990 | 0.31 | d | 0.00 | 0.39 | 2.04 | 2.81 | 1.21 | 1.49 | 1.48 | 0.31 | 1.39 | 0.30 | 0.53 | 12.26 | ||||||||||||
| 1991 | 0.05 | 0.30 | 0.99 | 2.53 | 3.85 | 1.90 | 0.65 | 0.59 | 3.51 | 0.51 | 1.10 | 0.06 | 16.04 | |||||||||||||
| 1992 | 0.07 | a | 0.00 | 1.21 | 0.98 | 1.42 | 5.76 | 1.85 | 0.75 | 0.39 | 0.66 | 0.62 | 0.32 | 14.03 | ||||||||||||
| 1993 | 0.36 | 0.03 | 0.47 | 1.22 | 1.87 | 1.28 | 2.02 | 0.99 | 0.40 | 1.30 | b | 0.19 | 0.05 | 10.18 | ||||||||||||
| 1994 | 0.07 | 0.88 | 0.23 | 1.18 | 1.12 | 0.58 | 1.47 | 0.85 | 1.18 | 3.37 | 0.85 | 0.37 | 12.15 | |||||||||||||
| 1995 | 0.43 | 0.46 | 1.17 | 1.44 | 2.40 | 1.97 | 1.36 | 0.28 | 2.66 | 0.83 | 0.82 | b | 0.18 | 14.00 | ||||||||||||
| 1996 | 0.44 | 0.28 | 1.01 | 1.15 | 2.36 | 0.88 | 0.19 | 0.67 | 2.21 | 0.65 | a | 0.75 | 1.10 | 11.69 | ||||||||||||
| 1997 | 0.50 | 0.35 | 0.53 | 1.22 | 1.18 | 2.36 | 3.23 | 1.31 | 0.97 | 1.38 | 0.40 | 0.45 | 13.88 | |||||||||||||
| 1998 | 1.33 | 0.02 | a | 0.28 | 0.86 | 0.72 | 2.35 | 1.48 | 1.59 | 1.02 | 0.96 | 0.73 | a | 0.53 | 11.87 | |||||||||||
| 1999 | 0.38 | 0.00 | 0.20 | 3.50 | 1.98 | 2.47 | 0.40 | 2.54 | 0.86 | 0.53 | 0.06 | 0.28 | 13.20 | |||||||||||||
| 2000 | 1.63 | 0.99 | 0.32 | 1.45 | 1.38 | 1.27 | 0.64 | 0.38 | 0.69 | 0.80 | 0.34 | 0.27 | 10.16 | |||||||||||||
| 2001 | 0.10 | 0.67 | 0.97 | 0.15 | 1.28 | 3.09 | 0.16 | 0.74 | 1.28 | 0.46 | 0.11 | 0.21 | 9.22 | |||||||||||||
| 2002 | 0.36 | 0.60 | 1.13 | 0.70 | 0.37 | 0.62 | 2.05 | 1.27 | 0.72 | 1.38 | 0.25 | 0.00 | a | 9.45 | ||||||||||||
| 2003 | 0.61 | b | 0.42 | 1.45 | 0.44 | 0.80 | 0.97 | 0.10 | 0.40 | 0.59 | 0.52 | 0.97 | 0.47 | 7.74 | ||||||||||||
| 2004 | 0.05 | 0.39 | 0.02 | 0.55 | 1.01 | 1.17 | 0.98 | 1.31 | 0.65 | 1.01 | 0.73 | 0.11 | a | 7.98 | ||||||||||||
| 2005 | 0.28 | a | 0.29 | b | 0.37 | 1.76 | 3.47 | 1.81 | 0.37 | 1.01 | 0.71 | 0.69 | 0.88 | a | 0.07 | 11.71 | ||||||||||
| 2006 | 0.08 | 0.13 | a | 0.37 | 0.84 | 0.91 | 1.12 | 0.51 | 0.11 | 1.35 | 0.76 | 0.35 | 0.24 | b | 6.77 | |||||||||||
| 2007 | 0.33 | 0.52 | 1.01 | 1.58 | 0.65 | 2.22 | 0.31 | 1.09 | 0.34 | 1.47 | 0.27 | 0.25 | 10.04 | |||||||||||||
| 2008 | 0.02 | 0.28 | 0.45 | 0.22 | 4.58 | 0.32 | 0.26 | 0.88 | 2.17 | 0.49 | 0.09 | 0.67 | b | 10.43 | ||||||||||||
| 2009 | 0.70 | 0.33 | 0.31 | 1.00 | 0.81 | 3.09 | 2.28 | c | 0.73 | 0.12 | 0.98 | 0.00 | 0.13 | l | 10.35 | |||||||||||
| 2010 | 0.00 | z | 0.12 | 0.24 | 0.65 | 1.50 | 0.98 | 0.81 | 1.62 | 0.14 | 0.14 | 0.19 | 0.09 | 6.48 | ||||||||||||
| 2011 | 0.22 | 0.52 | 0.38 | 2.45 | 5.15 | 1.24 | 0.51 | 0.68 | 0.25 | 1.63 | a | 1.33 | 0.62 | 14.98 | ||||||||||||
| 2012 | 0.16 | 0.60 | 0.36 | 0.29 | 1.72 | a | 0.00 | a | 0.33 | 0.06 | 0.00 | 0.34 | 0.52 | 0.59 | 4.97 | |||||||||||
| 2013 | 0.30 | 0.19 | 0.31 | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.80 | ||||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 0.34 | 0.30 | 0.53 | 1.07 | 1.66 | 1.62 | 1.03 | 0.80 | 1.01 | 0.77 | 0.49 | 0.32 | 9.85 | |||||||||||||
| S.D. | 0.38 | 0.27 | 0.37 | 0.69 | 1.07 | 1.00 | 0.75 | 0.60 | 0.84 | 0.66 | 0.36 | 0.28 | 2.56 | |||||||||||||
| SKEW | 2.25 | 1.57 | 1.05 | 0.94 | 0.99 | 1.15 | 1.03 | 0.99 | 1.16 | 1.41 | 1.07 | 1.09 | 0.15 | |||||||||||||
| MAX | 1.92 | 1.38 | 1.70 | 3.50 | 5.15 | 5.76 | 3.27 | 2.58 | 3.51 | 3.37 | 1.81 | 1.17 | 16.04 | |||||||||||||
| MIN | 0.00 | 0.00 | 0.00 | 0.02 | 0.02 | 0.00 | 0.02 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 3.58 | |||||||||||||
| NO YRS | 96 | 97 | 97 | 95 | 96 | 97 | 97 | 97 | 96 | 94 | 95 | 94 | 90 | |||||||||||||