| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1970 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 18.31 | e | ----- | z | -10.84 | 3.73 | j | |
| 1971 | -33.15 | d | -7.00 | a | 10.75 | w | 33.46 | b | 51.10 | a | 74.65 | j | 65.00 | x | 63.80 | a | 48.75 | b | 24.20 | a | 2.79 | b | ----- | z | 22.99 | d |
| 1972 | -23.90 | a | -5.48 | 3.71 | 25.93 | a | ----- | z | 62.17 | 70.87 | 67.88 | w | 46.61 | b | 28.00 | b | ----- | z | -3.03 | 22.76 | c | |||||
| 1973 | ----- | z | 0.04 | ----- | z | 37.43 | 55.61 | 68.13 | ----- | z | 60.23 | 53.27 | 22.27 | a | -5.57 | 8.32 | 33.30 | c | ||||||||
| 1974 | -19.84 | -16.82 | 19.89 | m | 35.40 | 58.45 | b | 64.14 | b | 67.29 | 64.81 | ----- | z | 23.69 | b | -0.73 | -10.10 | 26.63 | b | |||||||
| 1975 | -11.00 | 7.00 | 19.23 | 29.13 | ----- | z | 65.80 | 71.67 | a | 62.42 | 44.40 | 26.03 | 1.89 | b | -9.81 | 27.89 | a | |||||||||
| 1976 | -2.61 | -4.66 | 17.03 | 39.03 | 52.32 | 65.73 | 68.71 | 69.13 | 53.20 | 27.52 | 23.47 | 5.83 | a | 34.56 | ||||||||||||
| 1977 | 16.77 | 18.14 | 11.17 | a | ----- | z | 52.42 | 66.77 | 73.00 | a | 71.03 | 50.13 | 29.26 | 0.97 | -9.03 | 34.60 | a | |||||||||
| 1978 | 13.71 | 9.67 | a | 19.94 | 36.34 | a | 54.55 | b | 61.18 | b | 70.48 | 66.97 | 54.63 | 23.83 | a | 15.50 | 6.61 | 36.12 | ||||||||
| 1979 | 9.16 | -8.00 | 17.29 | c | 31.30 | 57.97 | 63.07 | a | 67.45 | 66.63 | a | 51.30 | 33.58 | 24.83 | -11.53 | a | 33.59 | |||||||||
| 1980 | -7.65 | 17.71 | a | 20.07 | a | 34.93 | a | 57.71 | 62.77 | 68.42 | 60.97 | ----- | z | ----- | z | ----- | z | ----- | z | 39.37 | d | |||||
| 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 |
| 2011 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 2012 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 2013 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 2014 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| 2015 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 40.17 | x | 32.61 | h | 15.00 | -2.69 | b | 6.16 | j | |
| 2016 | 14.06 | 11.43 | v | ----- | z | ----- | z | 58.00 | r | ----- | z | ----- | z | ----- | z | 39.62 | v | 33.87 | 8.14 | b | -5.67 | a | 12.60 | h | ||
| 2017 | 10.53 | n | 12.75 | x | 9.04 | f | 36.79 | a | 56.30 | a | 69.79 | a | 73.96 | d | 59.23 | 52.10 | 29.57 | a | 7.41 | a | 23.65 | k | 48.14 | d | ||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | -4.44 | 1.06 | 15.49 | 33.98 | 55.16 | 64.96 | 70.21 | 64.52 | 50.49 | 26.68 | 8.52 | -3.81 | 34.75 | |||||||||||||
| S.D. | 17.65 | 11.65 | 6.02 | 4.08 | 2.72 | 2.77 | 2.40 | 3.92 | 3.37 | 4.57 | 10.00 | 7.52 | 1.28 | |||||||||||||
| SKEW | -0.23 | 0.22 | -1.21 | -0.77 | -0.23 | 0.33 | 0.23 | 0.23 | -0.60 | 0.01 | 0.40 | 0.59 | 0.28 | |||||||||||||
| MAX | 16.77 | 18.14 | 20.07 | 39.03 | 58.45 | 69.79 | 73.96 | 71.03 | 54.63 | 33.87 | 24.83 | 8.32 | 36.12 | |||||||||||||
| MIN | -33.15 | -16.82 | 3.71 | 25.93 | 51.10 | 61.18 | 67.29 | 59.23 | 44.40 | 18.31 | -5.57 | -11.53 | 33.59 | |||||||||||||
| YRS | 10 | 10 | 7 | 10 | 9 | 10 | 9 | 10 | 9 | 12 | 11 | 11 | 3 | |||||||||||||