Lettau 18Z temperature 1986 - -16.5 -29.0 -31.2 -25.1 -35.2 -39.7 -42.8 -47.2 -31.1 -15.8 -7.6 1987 -6.4 -19.2 -35.3 -37.8 -35.8 -29.9 -34.5 -38.2 -37.7 -27.1 -19.3 -6.1 1988 -7.5 -17.6 -31.7 -31.2 -32.9 -34.3 -35.5 -27.1 -34.9 -23.5 -17.0 -6.9 1989 -7.1 -20.2 -28.2 -28.2 -35.4 -46.2 -37.0 -37.2 -34.9 -27.5 -14.2 -5.8 1990 -7.6 -19.0 -30.3 -31.6 -35.2 -34.8 -40.6 -40.3 -41.5 -29.9 -16.2 -5.5 1991 -8.7 -14.2 -31.7 -30.5 -32.9 -32.8 -39.6 - - - -15.1 -5.4 1992 -6.9 -18.5 -22.7 -37.9 -29.9 -35.3 - - - - -15.9 -6.6 1993 -7.8 -17.2 -30.6 -33.3 -40.8 - - - - - -16.7 -9.9 1994 -9.1 -18.9 -32.9 -27.3 -41.8 -35.3 -33.5 -41.2 -45.8 -24.9 -15.3 -5.6 1995 -8.4 -16.8 -29.1 -37.8 -40.2 -30.3 - - - - -14.3 -5.7 1996 -6.7 - - - - - - - - - - -5.5 1997 -7.4 - - - - - - - - - - - 1998 - - -29.8 -40.9 -33.9 - - - - - - - 1999 - -19.0 -33.1 -39.9 -39.6 -38.8 -32.9 -41.6 -29.3 -25.9 - - 2000 - - -25.0 -30.6 -34.2 -34.3 -32.7 -36.5 -35.4 -29.4 - - 2001 - - -31.8 -30.2 -37.4 -31.3 -31.3 -47.8 -35.6 -27.9 - - 2002 - - -22.3 -34.5 -27.7 -42.8 -43.0 -40.6 -31.0 -26.1 - - 2003 - - - - - -33.7 -33.1 - - -23.9 - - 2004 - - - - - - - - - - - - 2005 - - -28.4 -36.9 - -33.9 -31.7 -38.5 -36.2 -25.3 - - 2006 - - - - - - - - - - - - 2007 - - - - - - - - - - - - 2008 - - - - - - - - - - - - 2009 - - - - - - - - - - - -