| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 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 | -4.00 | a | ----- | z |
| 2004 | -12.00 | -9.00 | 14.00 | 20.00 | 29.00 | 34.00 | 45.00 | 37.00 | a | 24.00 | 20.00 | -9.00 | -5.00 | b | -12.00 | c | ||||||||||
| 2005 | -5.00 | a | ----- | z | 4.00 | 19.00 | 30.00 | 29.00 | 43.00 | 35.00 | 32.00 | 22.00 | 4.00 | -9.00 | ----- | z | ||||||||||
| 2006 | -3.00 | -4.00 | 7.00 | 12.00 | 29.00 | h | 37.00 | c | 48.00 | 41.00 | 26.00 | 19.00 | -11.00 | -5.00 | -11.00 | k | ||||||||||
| 2007 | -19.00 | -0.00 | 3.00 | 17.00 | 25.00 | 30.00 | a | 49.00 | 46.00 | 21.00 | 18.00 | 7.00 | -9.00 | -19.00 | a | |||||||||||
| 2008 | -13.00 | -4.00 | 1.00 | a | ----- | z | ----- | z | 30.00 | 47.00 | 41.00 | 30.00 | 16.00 | 7.00 | -10.00 | ----- | z | |||||||||
| 2009 | -15.00 | -2.00 | a | 8.00 | c | 11.00 | 26.00 | 31.00 | 43.00 | 37.00 | 28.00 | 11.00 | a | 4.00 | -15.00 | -15.00 | e | |||||||||
| 2010 | -3.00 | -1.00 | 9.00 | 7.00 | 19.00 | a | 28.00 | 37.00 | 36.00 | 31.00 | a | 15.00 | -15.00 | -9.00 | -15.00 | b | ||||||||||
| 2011 | -18.00 | -22.00 | ----- | z | 11.00 | 24.00 | 31.00 | 45.00 | 44.00 | 38.00 | 15.00 | 9.00 | -4.00 | ----- | z | |||||||||||
| 2012 | -3.00 | -0.00 | -2.00 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | |||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | -10.11 | -5.25 | 5.50 | 13.86 | 25.50 | 31.25 | 44.63 | 39.63 | 28.75 | 17.00 | -0.50 | -7.78 | -15.33 | |||||||||||||
| S.D. | 6.66 | 7.38 | 5.04 | 4.85 | 3.94 | 2.92 | 3.78 | 4.00 | 5.26 | 3.46 | 9.53 | 3.63 | 3.51 | |||||||||||||
| SKEW | -0.06 | -1.65 | 0.17 | 0.04 | -0.52 | 0.99 | -0.90 | 0.40 | 0.26 | -0.26 | -0.52 | -0.67 | -0.17 | |||||||||||||
| MAX | -3.00 | -0.00 | 14.00 | 20.00 | 30.00 | 37.00 | 49.00 | 46.00 | 38.00 | 22.00 | 9.00 | -4.00 | -12.00 | |||||||||||||
| MIN | -19.00 | -22.00 | -2.00 | 7.00 | 19.00 | 28.00 | 37.00 | 35.00 | 21.00 | 11.00 | -15.00 | -15.00 | -19.00 | |||||||||||||
| YRS | 9 | 8 | 8 | 7 | 6 | 8 | 8 | 8 | 8 | 8 | 8 | 9 | 3 | |||||||||||||