Gill 18Z temperature 1985 - -18.5 -28.0 -38.7 -35.6 -38.7 -51.4 -43.5 -41.6 -30.2 -18.6 -10.1 1986 -10.1 -18.3 -29.0 -34.3 -26.8 -35.1 -41.6 -47.9 -48.8 -33.0 -17.7 -9.3 1987 -8.3 -17.8 -37.0 -39.2 -38.3 -31.2 -33.7 -40.4 -38.8 -28.8 -21.8 -7.7 1988 -8.3 -19.6 -33.0 -33.8 -33.3 -35.5 -37.3 -31.4 -37.4 -28.1 -18.5 -7.5 1989 -8.5 -21.1 -28.6 -28.2 -39.0 -47.7 - - - - - - 1990 - - - - - - - - - - - - 1991 - -14.8 -32.6 -32.8 -34.5 -34.4 -41.3 -41.9 -34.4 -27.7 -17.3 -6.4 1992 -7.0 -18.5 -21.2 -37.8 -33.2 -36.3 -34.7 -44.4 - - -18.0 -8.1 1993 -8.3 -17.5 -31.8 -34.9 -41.0 -31.8 -33.9 -41.9 - - -18.0 -10.5 1994 -11.2 -21.7 -34.6 -29.7 -42.8 -40.0 -35.9 - - - - -7.1 1995 -9.3 -17.7 -29.2 -39.0 -40.6 -32.5 -41.5 - - - - -8.1 1996 -8.7 -20.4 -35.3 -29.1 -37.9 -36.7 -41.5 -33.6 -39.0 -35.7 -16.7 -9.1 1997 -9.4 -18.9 -31.7 -42.4 -36.0 -34.1 -40.1 -45.7 -38.9 -24.4 -13.5 -8.5 1998 -10.3 -15.6 -29.8 -41.3 -34.2 -30.3 -45.1 -39.8 -43.4 -29.9 -19.8 -9.9 1999 -10.2 -20.3 -35.8 -40.3 -42.6 -39.1 -31.8 -43.9 -32.3 -28.7 -16.9 -10.4 2000 -11.5 -19.0 -24.8 -32.7 -36.6 -38.8 -36.3 -38.8 -38.3 -31.3 -15.2 -10.2 2001 -13.1 -18.5 -33.5 -33.0 -38.6 -37.2 -36.1 -49.7 -39.7 -30.6 -19.3 -9.3 2002 -9.7 -18.8 -25.1 -35.9 -32.1 -42.1 -46.3 -43.6 -32.0 -25.2 -16.4 -9.7 2003 - - - -36.2 - -35.0 -36.6 - - - - - 2004 - - - - - - - - - - - - 2005 - -20.9 -31.8 -38.9 - -37.1 -35.9 -41.9 -39.6 -29.9 -17.6 -8.0 2006 -10.6 - - - - - - - - - - - 2007 - - - -32.9 -36.6 -36.8 - -38.6 -35.8 -32.9 -16.6 -7.8 2008 -6.8 -19.1 -29.9 -33.4 -36.3 -33.2 -41.5 -51.1 -37.1 -28.0 - - 2009 - - - - - - - - - - - -