| 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 | 5.79 | e | ----- | z | -20.55 | a | -7.38 | j |
| 1971 | -42.35 | e | -21.15 | a | -10.69 | w | 10.63 | c | 38.98 | a | 59.33 | j | 54.00 | x | 50.13 | a | 39.09 | c | 9.12 | b | -6.56 | c | ----- | z | 9.74 | d |
| 1972 | -30.79 | c | -19.69 | -14.34 | 13.07 | a | ----- | z | 52.00 | 56.89 | 52.62 | w | 35.39 | c | 20.50 | d | ----- | z | -12.89 | 11.13 | c | |||||
| 1973 | ----- | z | -16.48 | ----- | z | 20.67 | 42.35 | 53.45 | ----- | z | 46.81 | 38.65 | c | 11.90 | a | -15.71 | a | -4.77 | 19.65 | c | ||||||
| 1974 | -28.45 | -32.05 | 2.83 | m | 20.40 | 42.00 | b | 51.13 | c | 57.05 | i | 53.66 | ----- | z | 15.07 | b | -7.97 | -17.68 | 10.68 | c | ||||||
| 1975 | -19.75 | a | -2.31 | a | 8.23 | 17.33 | ----- | z | 54.23 | 60.47 | a | 52.35 | 37.68 | 18.47 | -6.34 | b | -17.29 | b | 18.46 | a | ||||||
| 1976 | -9.44 | -15.78 | 7.23 | 27.82 | 42.84 | 56.57 | 58.11 | 55.79 | 42.37 | 20.45 | 14.48 | a | -3.33 | a | 24.76 | |||||||||||
| 1977 | 8.68 | 8.45 | -2.13 | a | ----- | z | 41.77 | 54.60 | 58.70 | a | 56.84 | 39.28 | a | 19.68 | -7.40 | -14.45 | 24.00 | a | ||||||||
| 1978 | 5.87 | 0.02 | a | 7.39 | 25.43 | a | 42.11 | c | 51.30 | b | 58.19 | 53.21 | 43.03 | 15.25 | a | 6.23 | -2.34 | 25.47 | ||||||||
| 1979 | -0.16 | -20.80 | 5.79 | c | 20.17 | 45.95 | 52.66 | a | 56.47 | 55.53 | a | 40.03 | 26.69 | 16.70 | -19.63 | a | 23.28 | |||||||||
| 1980 | -16.27 | 6.91 | a | 10.02 | a | 24.90 | a | 47.08 | 52.73 | 57.66 | 49.42 | ----- | z | ----- | z | ----- | z | ----- | z | 29.06 | 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 | 33.83 | x | 23.46 | h | 6.87 | -12.50 | b | -2.82 | j | |
| 2016 | 3.05 | 0.50 | v | ----- | z | ----- | z | 46.85 | r | ----- | z | ----- | z | ----- | z | 35.00 | v | 20.95 | -1.55 | b | -11.88 | a | 2.64 | h | ||
| 2017 | 2.06 | n | 4.38 | x | -10.22 | f | 20.95 | a | 43.20 | a | 54.55 | a | 60.02 | d | 49.18 | 42.10 | 22.97 | a | -1.41 | a | 15.28 | k | 36.44 | d | ||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | -12.96 | -11.29 | 3.17 | 20.14 | 42.92 | 53.32 | 58.31 | 52.29 | 39.74 | 17.24 | -0.24 | -12.48 | 24.51 | |||||||||||||
| S.D. | 17.43 | 13.60 | 8.64 | 5.36 | 2.38 | 1.70 | 1.39 | 3.31 | 2.46 | 6.02 | 10.13 | 6.46 | 1.12 | |||||||||||||
| SKEW | -0.27 | 0.20 | -1.37 | -0.40 | 0.35 | 0.41 | 0.31 | -0.18 | -0.22 | -0.45 | 0.37 | 0.44 | -0.40 | |||||||||||||
| MAX | 8.68 | 8.45 | 10.02 | 27.82 | 47.08 | 56.57 | 60.47 | 56.84 | 43.03 | 26.69 | 16.70 | -2.34 | 25.47 | |||||||||||||
| MIN | -42.35 | -32.05 | -14.34 | 10.63 | 38.98 | 51.13 | 56.47 | 46.81 | 35.39 | 5.79 | -15.71 | -20.55 | 23.28 | |||||||||||||
| YRS | 10 | 10 | 7 | 10 | 9 | 10 | 8 | 10 | 9 | 12 | 11 | 11 | 3 | |||||||||||||