| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 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 | 48.00 | b | 38.00 | b | 33.00 | d | 16.00 | d | 17.00 | e | ----- | z |
| 1986 | 24.00 | c | 13.00 | f | 27.00 | b | 27.00 | e | 35.00 | e | 49.00 | c | 40.00 | e | 55.00 | f | 35.00 | f | 28.00 | e | 20.00 | i | 16.00 | g | ----- | z |
| 1987 | 19.00 | i | 17.00 | h | 23.00 | g | 32.00 | e | 40.00 | l | 45.00 | g | 45.00 | k | 49.00 | l | 47.00 | h | 40.00 | g | 23.00 | g | 12.00 | g | ----- | z |
| 1988 | 17.00 | e | 26.00 | a | 20.00 | c | 31.00 | f | 26.00 | b | 36.00 | a | 46.00 | 46.00 | d | 42.00 | e | 40.00 | g | 22.00 | e | 12.00 | k | ----- | z | |
| 1989 | 15.00 | c | 6.00 | c | 26.00 | c | 35.00 | a | 38.00 | a | 46.00 | 49.00 | 46.00 | e | 41.00 | h | 28.00 | c | 20.00 | b | 17.00 | b | ----- | z | ||
| 1990 | 17.00 | 13.00 | 24.00 | 35.00 | 37.00 | 47.00 | c | 52.00 | 48.00 | a | 45.00 | a | 32.00 | b | 22.00 | a | 1.00 | 1.00 | h | |||||||
| 1991 | 19.00 | 22.00 | 23.00 | 27.00 | 33.00 | a | 41.00 | 52.00 | a | 50.00 | 44.00 | c | 28.00 | 20.00 | 21.00 | 19.00 | e | |||||||||
| 1992 | 22.00 | 25.00 | 31.00 | 39.00 | 40.00 | d | 42.00 | a | 51.00 | c | 49.00 | c | 46.00 | d | 35.00 | 23.00 | a | 16.00 | 16.00 | p | ||||||
| 1993 | 16.00 | 24.00 | 26.00 | 33.00 | b | 34.00 | 43.00 | 44.00 | 46.00 | f | 38.00 | b | 28.00 | a | 19.00 | 19.00 | a | 16.00 | l | |||||||
| 1994 | 17.00 | c | 21.00 | 31.00 | 30.00 | b | 33.00 | a | 45.00 | b | 53.00 | a | 50.00 | 43.00 | e | 28.00 | e | 16.00 | a | 20.00 | 16.00 | t | ||||
| 1995 | 20.00 | a | 26.00 | 26.00 | 21.00 | 32.00 | c | 38.00 | a | 46.00 | c | 47.00 | d | 43.00 | a | 30.00 | a | 23.00 | 23.00 | 20.00 | n | |||||
| 1996 | 16.00 | 13.00 | 24.00 | a | 28.00 | 34.00 | 46.00 | 52.00 | 48.00 | 39.00 | 24.00 | 26.00 | 17.00 | 13.00 | a | |||||||||||
| 1997 | 12.00 | 21.00 | 22.00 | 24.00 | 37.00 | a | 41.00 | 42.00 | c | 53.00 | a | 49.00 | 28.00 | 26.00 | 17.00 | a | 12.00 | f | ||||||||
| 1998 | 18.00 | 21.00 | 20.00 | 28.00 | 33.00 | b | 39.00 | f | 49.00 | a | 48.00 | c | 40.00 | 30.00 | 21.00 | a | 14.00 | a | 14.00 | n | ||||||
| 1999 | 22.00 | a | 19.00 | b | 24.00 | 21.00 | 31.00 | a | 39.00 | a | 51.00 | 47.00 | a | 42.00 | a | 29.00 | 24.00 | 17.00 | b | 17.00 | i | |||||
| 2000 | ----- | z | 25.00 | c | 27.00 | 32.00 | c | 34.00 | e | 44.00 | 34.00 | b | 48.00 | e | 42.00 | e | 34.00 | d | 20.00 | f | 18.00 | b | ----- | z | ||
| 2001 | 18.00 | c | 17.00 | a | 24.00 | 24.00 | 35.00 | 36.00 | b | 48.00 | a | 50.00 | 45.00 | 34.00 | a | 22.00 | a | 17.00 | a | 17.00 | j | |||||
| 2002 | 16.00 | 19.00 | a | 16.00 | 33.00 | 32.00 | a | 40.00 | a | 59.00 | r | 48.00 | l | 42.00 | c | 34.00 | l | 25.00 | b | 17.00 | ----- | z | ||||
| 2003 | 25.00 | 17.00 | 23.00 | 24.00 | 33.00 | 49.00 | e | 52.00 | c | 52.00 | e | 46.00 | 38.00 | 18.00 | 16.00 | 16.00 | m | |||||||||
| 2004 | 14.00 | 18.00 | 26.00 | 35.00 | 39.00 | a | 43.00 | a | 49.00 | a | 51.00 | 40.00 | 29.00 | d | 22.00 | a | 17.00 | b | 14.00 | j | ||||||
| 2005 | 22.00 | c | 26.00 | a | 25.00 | c | 28.00 | c | 35.00 | e | 41.00 | b | 40.00 | b | 55.00 | a | 43.00 | 41.00 | 19.00 | 16.00 | 16.00 | t | ||||
| 2006 | 20.00 | 24.00 | 24.00 | 31.00 | 42.00 | 51.00 | a | 58.00 | b | 55.00 | d | 45.00 | d | 31.00 | h | 20.00 | i | 18.00 | c | ----- | z | |||||
| 2007 | 11.00 | 19.00 | 24.00 | 35.00 | 37.00 | b | 50.00 | c | 58.00 | b | 54.00 | e | 45.00 | a | 34.00 | g | 21.00 | j | 16.00 | d | ----- | z | ||||
| 2008 | ----- | z | 23.00 | a | 26.00 | a | 32.00 | a | 33.00 | c | 42.00 | c | 57.00 | a | 54.00 | 46.00 | 30.00 | a | 26.00 | ----- | z | ----- | z | |||
| 2009 | 19.00 | 22.00 | 21.00 | 29.00 | 40.00 | d | 44.00 | a | 53.00 | a | 51.00 | 48.00 | 26.00 | 27.00 | 14.00 | 14.00 | f | |||||||||
| 2010 | 22.00 | 28.00 | a | 26.00 | 28.00 | j | 34.00 | b | 47.00 | 52.00 | a | 47.00 | b | 45.00 | a | 34.00 | 18.00 | a | 13.00 | a | 13.00 | s | ||||
| 2011 | 11.00 | b | 12.00 | a | 25.00 | 23.00 | 33.00 | a | 35.00 | a | 51.00 | 48.00 | c | 48.00 | a | 34.00 | c | 23.00 | e | 15.00 | 11.00 | q | ||||
| 2012 | 17.00 | c | 20.00 | e | 20.00 | 27.00 | b | 46.00 | t | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 23.00 | h | 25.00 | r | ----- | z | |
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 17.92 | 20.28 | 24.27 | 29.32 | 34.80 | 43.13 | 49.13 | 49.78 | 43.50 | 30.95 | 21.73 | 16.35 | 13.00 | |||||||||||||
| S.D. | 3.81 | 5.22 | 3.27 | 4.83 | 3.40 | 4.50 | 5.88 | 2.86 | 3.06 | 4.05 | 3.22 | 4.02 | 0.0 | |||||||||||||
| SKEW | -0.08 | -0.89 | -0.20 | -0.04 | -0.03 | -0.07 | -0.74 | 0.55 | -0.17 | 0.68 | -0.14 | -2.30 | 0.00 | |||||||||||||
| MAX | 25.00 | 28.00 | 31.00 | 39.00 | 42.00 | 51.00 | 58.00 | 55.00 | 49.00 | 41.00 | 27.00 | 23.00 | 13.00 | |||||||||||||
| MIN | 11.00 | 6.00 | 16.00 | 21.00 | 26.00 | 35.00 | 34.00 | 46.00 | 38.00 | 24.00 | 16.00 | 1.00 | 13.00 | |||||||||||||
| YRS | 24 | 25 | 26 | 25 | 25 | 24 | 24 | 23 | 24 | 22 | 22 | 23 | 1 | |||||||||||||