| 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 | -35.00 | a | -62.00 | g | -68.00 | a | ----- | z |
| 1971 | -80.00 | d | -64.00 | -62.00 | u | -43.00 | b | 7.00 | a | 20.00 | i | 34.00 | x | 24.00 | a | 15.00 | c | -32.00 | a | -52.00 | b | ----- | z | ----- | z | |
| 1972 | -70.00 | b | -56.00 | -54.00 | -34.00 | ----- | z | 29.00 | 33.00 | 32.00 | v | 6.00 | b | -22.00 | b | ----- | z | -54.00 | ----- | z | ||||||
| 1973 | ----- | z | -55.00 | ----- | z | -15.00 | 18.00 | 30.00 | ----- | z | 22.00 | 7.00 | c | -20.00 | -50.00 | a | -46.00 | ----- | z | |||||||
| 1974 | -60.00 | -63.00 | -56.00 | -22.00 | 7.00 | b | 28.00 | c | 32.00 | i | 19.00 | ----- | z | -8.00 | b | -48.00 | -57.00 | ----- | z | |||||||
| 1975 | -58.00 | a | -37.00 | a | -29.00 | -21.00 | ----- | z | 31.00 | 31.00 | 30.00 | 11.00 | -33.00 | -33.00 | -49.00 | b | ----- | z | ||||||||
| 1976 | -43.00 | -55.00 | -29.00 | -18.00 | 24.00 | 32.00 | 34.00 | 33.00 | 21.00 | -21.00 | -21.00 | a | -41.00 | -55.00 | a | |||||||||||
| 1977 | -39.00 | -41.00 | -39.00 | ----- | z | 10.00 | 34.00 | 35.00 | 17.00 | 11.00 | a | -21.00 | -36.00 | -47.00 | ----- | z | ||||||||||
| 1978 | -25.00 | -46.00 | -23.00 | -16.00 | 20.00 | a | 34.00 | 37.00 | 25.00 | 7.00 | -12.00 | -30.00 | -45.00 | -46.00 | a | |||||||||||
| 1979 | -37.00 | -50.00 | -29.00 | -19.00 | 25.00 | 25.00 | 37.00 | 28.00 | 7.00 | -0.00 | -15.00 | -49.00 | -50.00 | |||||||||||||
| 1980 | -52.00 | -38.00 | -36.00 | -7.00 | 26.00 | 31.00 | 35.00 | 25.00 | ----- | 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 | ----- | 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 | 23.00 | x | 0.00 | h | -34.00 | -40.00 | b | ----- | z | |
| 2016 | -35.00 | -22.00 | v | ----- | z | ----- | z | 26.00 | r | ----- | z | ----- | z | ----- | z | 23.00 | v | -12.00 | -37.00 | b | -40.00 | a | ----- | z | ||
| 2017 | -38.00 | n | -23.00 | x | -40.00 | f | -14.00 | a | 22.00 | a | 29.00 | a | 38.00 | d | 20.00 | 14.00 | -17.00 | a | -37.00 | a | -14.00 | k | ----- | z | ||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | -49.90 | -50.50 | -36.88 | -20.90 | 17.67 | 30.30 | 35.00 | 24.30 | 11.00 | -19.42 | -35.73 | -48.73 | -50.33 | |||||||||||||
| S.D. | 17.18 | 9.77 | 12.21 | 10.40 | 7.70 | 2.75 | 2.33 | 5.03 | 4.97 | 10.54 | 11.46 | 8.39 | 4.51 | |||||||||||||
| SKEW | -0.33 | 0.08 | -0.66 | -1.01 | -0.45 | -0.33 | -0.36 | 0.24 | 0.83 | 0.11 | 0.23 | -1.07 | -0.14 | |||||||||||||
| MAX | -25.00 | -37.00 | -23.00 | -7.00 | 26.00 | 34.00 | 38.00 | 33.00 | 21.00 | -0.00 | -15.00 | -40.00 | -46.00 | |||||||||||||
| MIN | -80.00 | -64.00 | -56.00 | -43.00 | 7.00 | 25.00 | 31.00 | 17.00 | 6.00 | -35.00 | -52.00 | -68.00 | -55.00 | |||||||||||||
| YRS | 10 | 10 | 8 | 10 | 9 | 10 | 8 | 10 | 9 | 12 | 11 | 11 | 3 | |||||||||||||