| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1941 | 0.80 | 0.42 | 2.03 | 2.70 | 7.59 | 3.61 | 3.31 | 1.06 | 5.25 | 6.01 | 0.07 | 0.26 | 33.11 | |||||||||||||
| 1942 | 0.00 | 0.43 | 0.07 | 3.47 | 0.27 | 0.97 | 1.35 | 2.96 | 1.83 | 2.34 | 0.00 | 0.61 | 14.30 | |||||||||||||
| 1943 | 0.00 | 0.03 | 0.00 | 0.00 | 2.01 | 2.23 | 1.79 | 1.69 | 0.00 | z | 0.08 | 0.03 | 0.86 | 8.72 | ||||||||||||
| 1944 | 0.37 | 0.25 | 0.00 | 0.99 | 1.43 | 1.24 | 2.45 | 4.03 | 1.12 | 0.73 | 2.23 | 0.73 | 15.57 | |||||||||||||
| 1945 | 0.73 | 0.03 | 0.03 | 0.25 | 2.27 | 0.78 | 1.62 | 5.50 | 1.74 | 1.49 | 0.00 | 0.03 | 14.47 | |||||||||||||
| 1946 | 0.04 | 0.04 | 0.16 | 0.09 | 0.69 | 0.11 | 1.14 | 2.30 | 2.66 | 1.43 | 1.12 | 0.00 | 9.78 | |||||||||||||
| 1947 | 0.00 | z | 0.00 | 0.00 | z | 0.97 | 0.00 | z | 0.00 | z | 1.12 | 1.97 | 0.10 | 0.13 | 0.44 | 0.94 | 5.67 | |||||||||
| 1948 | 0.38 | 1.08 | 0.67 | 0.39 | 1.88 | 2.62 | 2.10 | 3.29 | 0.00 | a | 1.70 | a | 0.26 | 0.00 | 14.37 | |||||||||||
| 1949 | 0.83 | 1.64 | 0.43 | 1.57 | a | 2.08 | 6.22 | 3.84 | 0.81 | 0.82 | 0.49 | 0.00 | a | 0.30 | a | 19.03 | ||||||||||
| 1950 | 0.00 | 0.00 | a | 0.00 | a | 0.40 | a | 0.41 | b | 2.84 | 10.29 | a | 1.12 | b | 2.24 | a | 0.06 | 0.00 | 0.36 | 17.72 | ||||||
| 1951 | 0.49 | 0.27 | 0.76 | 0.14 | 2.09 | 1.72 | 1.00 | 0.15 | 0.12 | 0.79 | 0.13 | 0.10 | 7.76 | |||||||||||||
| 1952 | 0.27 | 0.33 | 0.63 | 2.12 | 0.81 | 0.88 | 2.62 | 1.94 | 0.55 | 0.00 | 0.75 | 0.21 | 11.11 | |||||||||||||
| 1953 | 0.18 | 0.36 | 0.21 | 0.31 | 1.53 | 0.07 | 2.63 | 2.11 | 0.00 | 0.37 | a | 0.58 | 0.63 | 8.98 | ||||||||||||
| 1954 | 0.10 | 0.03 | a | 0.06 | 0.75 | 2.17 | 1.53 | 3.71 | 1.84 | 1.86 | a | 2.50 | 0.00 | z | 0.00 | z | 14.55 | |||||||||
| 1955 | 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 | |
| 1956 | 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 | |
| 1957 | 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 | |
| 1958 | 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 | |
| 1959 | 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 | |
| 1960 | 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 | |
| 1961 | 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 | |
| 1962 | 0.00 | z | 0.00 | z | 0.44 | 0.94 | 0.15 | 1.92 | 3.68 | 0.40 | 0.61 | 0.27 | 0.30 | 0.34 | 9.05 | |||||||||||
| 1963 | 0.03 | 1.13 | 0.00 | 0.22 | 2.58 | 1.34 | 2.59 | 4.65 | 0.70 | 0.68 | 0.01 | 0.04 | 13.97 | |||||||||||||
| 1964 | 0.01 | 0.71 | 0.14 | 0.36 | 0.91 | 0.06 | 2.37 | 1.03 | 1.39 | 0.02 | 1.51 | 0.54 | 9.05 | |||||||||||||
| 1965 | 0.10 | 0.25 | 0.65 | 1.07 | 3.22 | 1.71 | 3.80 | 1.67 | 0.93 | 0.76 | 0.00 | 0.38 | 14.54 | |||||||||||||
| 1966 | 0.33 | 0.50 | 0.00 | 0.04 | 0.91 | 1.43 | 2.41 | 2.91 | 0.18 | 0.02 | 0.00 | 0.04 | 8.77 | |||||||||||||
| 1967 | 0.00 | 0.28 | 0.03 | 0.40 | 0.72 | 0.85 | 6.89 | 1.88 | 2.99 | 0.35 | 0.04 | 0.49 | 14.92 | |||||||||||||
| 1968 | 1.18 | 0.24 | 0.45 | 0.64 | 1.46 | 0.14 | 2.03 | 1.88 | 0.15 | 0.80 | 0.54 | 0.35 | 9.86 | |||||||||||||
| 1969 | 0.00 | 0.85 | 0.47 | 1.16 | 5.03 | 3.40 | 4.22 | 5.62 | 2.85 | 2.18 | 0.46 | 1.07 | 27.31 | |||||||||||||
| 1970 | 0.02 | 0.06 | 0.54 | 1.72 | 0.28 | 0.73 | 5.05 | 1.77 | 3.31 | 1.31 | 0.00 | 0.00 | 14.79 | |||||||||||||
| 1971 | 0.22 | 0.32 | 0.02 | 0.54 | 1.51 | 4.27 | 1.30 | 1.73 | 1.66 | 1.95 | 1.43 | 0.57 | 15.52 | |||||||||||||
| 1972 | 0.00 | 0.05 | 0.02 | 0.00 | 0.39 | 1.19 | 4.64 | 6.33 | 5.01 | 1.80 | 0.80 | 0.10 | 20.33 | |||||||||||||
| 1973 | 0.49 | 0.33 | 2.02 | 1.13 | 0.51 | 0.28 | 3.65 | 1.52 | 0.61 | 0.85 | 0.00 | 0.60 | 11.99 | |||||||||||||
| 1974 | 0.57 | 0.17 | 0.03 | 0.34 | 0.19 | 0.75 | 2.17 | 2.27 | 2.35 | 4.46 | 0.42 | 0.35 | 14.07 | |||||||||||||
| 1975 | 0.38 | 1.29 | 0.34 | 1.09 | 0.82 | 0.42 | 3.92 | 0.85 | 1.54 | 0.01 | 0.53 | 0.15 | 11.34 | |||||||||||||
| 1976 | 0.15 | 0.00 | 0.27 | 1.04 | 0.54 | 2.46 | 6.10 | 1.10 | 1.64 | 0.83 | 0.20 | 0.00 | 14.33 | |||||||||||||
| 1977 | 0.37 | 0.92 | 0.22 | 3.44 | 0.93 | 1.37 | 3.36 | 1.45 | 0.30 | 0.26 | 0.29 | 0.00 | 12.91 | |||||||||||||
| 1978 | 0.41 | 0.46 | 0.23 | 0.60 | 2.74 | 3.58 | 1.78 | 0.71 | 0.88 | 0.17 | 2.87 | 0.23 | 14.66 | |||||||||||||
| 1979 | 0.33 | 0.01 | 0.60 | 0.94 | 3.34 | 2.41 | 4.26 | 2.35 | 0.94 | 1.10 | 1.58 | 0.08 | 17.94 | |||||||||||||
| 1980 | 0.26 | 0.42 | 0.66 | 2.42 | 2.46 | 0.16 | 0.42 | 6.65 | 1.46 | 0.14 | 0.43 | 0.01 | 15.49 | |||||||||||||
| 1981 | 0.10 | 0.06 | 0.86 | 0.34 | 0.78 | 2.83 | 0.74 | 6.96 | 3.20 | 1.40 | 0.13 | 0.00 | 17.40 | |||||||||||||
| 1982 | 0.04 | a | 0.15 | 0.33 | 0.37 | 1.33 | 2.73 | 0.72 | e | 0.00 | z | 2.85 | 0.00 | z | 0.00 | z | 0.00 | z | 8.52 | |||||||
| 1983 | 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 | |
| 1984 | 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 | |
| 1985 | 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 | |
| 1986 | 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 | |
| 1987 | 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 | |
| 1988 | 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 | |
| 1989 | 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 | |
| 1990 | 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 | |
| 1991 | 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 | |
| 1992 | 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 | |
| 1993 | 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 | |
| 1994 | 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 | |
| 1995 | 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 | |
| 1996 | 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 | |
| 1997 | 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 | |
| 1998 | 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 | |
| 1999 | 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 | |
| 2000 | 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 | |
| 2001 | 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 | |
| 2002 | 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 | |
| 2003 | 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 | |
| 2004 | 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 | |
| 2005 | 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 | |
| 2006 | 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 | |
| 2007 | 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 | |
| 2008 | 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 | |
| 2009 | 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 | |
| 2010 | 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 | |
| 2011 | 0.00 | 0.23 | 0.74 | 0.06 | k | 0.00 | 0.10 | 0.00 | b | 1.03 | e | 2.29 | a | 0.74 | 0.19 | 1.49 | e | 6.81 | ||||||||
| 2012 | 0.00 | 0.17 | c | 0.08 | a | 0.36 | b | 1.37 | 1.26 | a | 0.00 | j | 0.40 | 0.61 | 0.35 | 0.00 | 0.23 | 4.83 | ||||||||
| 2013 | 0.34 | 0.59 | 0.00 | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.16 | z | 0.93 | ||||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 0.26 | 0.38 | 0.38 | 0.93 | 1.59 | 1.67 | 2.92 | 2.39 | 1.58 | 1.07 | 0.50 | 0.35 | 14.85 | |||||||||||||
| S.D. | 0.29 | 0.40 | 0.48 | 0.91 | 1.50 | 1.39 | 2.02 | 1.84 | 1.32 | 1.26 | 0.68 | 0.36 | 5.28 | |||||||||||||
| SKEW | 1.27 | 1.44 | 2.15 | 1.48 | 2.13 | 1.14 | 1.49 | 1.22 | 1.03 | 2.23 | 1.90 | 1.27 | 1.66 | |||||||||||||
| MAX | 1.18 | 1.64 | 2.03 | 3.47 | 7.59 | 6.22 | 10.29 | 6.96 | 5.25 | 6.01 | 2.87 | 1.49 | 33.11 | |||||||||||||
| MIN | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.06 | 0.00 | 0.15 | 0.00 | 0.00 | 0.00 | 0.00 | 7.76 | |||||||||||||
| NO YRS | 36 | 37 | 37 | 36 | 36 | 36 | 36 | 36 | 36 | 36 | 35 | 35 | 30 | |||||||||||||