Ferrell 12Z temperature 1981 - -15.9 -21.5 -34.4 -31.6 -30.0 -33.8 -37.0 -37.9 -29.0 -20.3 -9.2 1982 -9.0 -15.1 -30.9 -35.9 -35.9 -35.2 -39.4 -32.1 -36.2 -28.5 -17.2 -8.5 1983 -9.0 -19.5 -25.3 -23.1 -24.4 -36.9 -37.3 - - - - - 1984 -10.3 -17.1 -23.1 -24.7 -28.3 -30.4 -35.2 -36.3 -35.0 - - - 1985 - -19.0 -24.9 -32.8 - - -42.5 -38.0 -34.1 -27.0 - - 1986 - -15.1 -23.1 -28.5 -24.4 -31.9 -34.7 -41.4 -42.7 -28.2 -17.1 -9.9 1987 - -17.7 -28.6 -32.0 -30.2 -28.3 -32.1 -36.0 -31.0 -27.6 -20.0 -8.0 1988 -9.0 -16.7 -27.6 -27.5 -28.5 -29.2 -35.0 -25.7 -28.0 -22.8 -16.8 -8.0 1989 -7.4 -18.2 -22.7 -24.0 - - - - - -23.7 -14.4 -7.8 1990 -9.2 -17.4 -27.3 -27.9 -29.4 -34.9 -35.1 -38.8 -38.1 -28.8 -17.2 -8.2 1991 -9.8 -13.2 -27.0 -27.7 -32.3 -28.0 - - - - -17.4 -7.7 1992 -9.4 -17.9 -20.6 -32.8 -29.6 -34.3 -31.0 - - - - - 1993 - -15.8 -25.3 -27.4 -34.9 -29.4 -31.0 -38.8 -32.9 -30.6 -16.7 -11.0 1994 -9.9 -16.6 -28.8 -24.2 -35.3 -33.0 -32.3 -38.2 -39.6 -24.1 -14.9 -8.1 1995 -9.4 -16.0 -27.4 -34.2 -35.3 -30.6 -35.1 -33.6 -33.0 -27.0 -15.7 -7.2 1996 -8.0 -16.7 -27.0 -25.9 -30.5 -32.0 -33.9 -27.5 -31.1 -29.1 -16.6 -7.2 1997 -8.4 -18.6 -29.5 -33.9 -30.4 -29.0 -34.9 -40.9 -31.6 -20.4 -10.7 -7.7 1998 -9.9 -12.7 -25.1 -36.3 -30.3 -23.6 -34.5 - - - - - 1999 - -16.4 - - - - - - - - - - 2000 - - - - - - - - - - - - 2001 - -14.6 -27.1 -27.0 -31.6 -27.5 -28.1 -41.7 -32.2 -26.5 -16.2 -7.3 2002 -8.3 -17.1 -21.6 -29.2 -26.8 -36.3 -38.2 -38.6 -28.6 -23.3 -15.9 -9.4 2003 - - - - - - - - - - - - 2004 - - - - - - - - - - - - 2005 - - - - - - - - - - - - 2006 - - - - - - - - - - -15.4 -8.4 2007 -5.6 -14.0 -22.5 -27.3 -26.8 -28.5 -29.6 -29.5 -28.1 -27.1 -14.6 -7.2 2008 -6.5 -16.3 -21.9 -26.1 -30.1 -23.8 -34.2 -41.9 -25.3 -22.7 - - 2009 - - - - - - - - - - - -