Lettau temperature 1986 - -15.7 -27.7 -31.4 -25.4 -34.4 -39.7 -42.9 -47.0 -30.3 -15.7 - 1987 -5.8 -17.9 -33.9 -37.7 -35.3 -30.6 -33.8 -39.0 -37.4 -26.1 -18.8 - 1988 -7.3 -17.2 -31.2 -31.3 -33.0 -34.6 -35.8 -27.0 -34.6 -22.6 -16.5 -6.7 1989 -6.5 -19.1 -27.2 -28.1 -35.1 -46.1 -37.4 -38.7 -34.8 -26.4 -13.8 -5.6 1990 -7.0 -18.2 -29.3 -31.5 -35.2 -34.8 -40.8 -40.5 -41.0 -28.9 -15.7 -5.1 1991 -8.0 -13.7 -30.6 -29.9 -33.5 -31.8 -39.9 - - - -14.5 -5.1 1992 -6.3 -17.4 -21.8 -38.1 -30.2 -35.4 - - - - -15.4 -6.2 1993 -6.7 -16.3 -29.6 -32.5 -41.0 - - - - - -16.0 -9.6 1994 -8.5 -17.8 -32.4 -27.7 -42.5 -35.6 -34.3 -41.7 -45.7 -24.8 -14.5 -5.3 1995 -7.7 -15.7 -28.8 -37.2 -40.6 -30.4 - - - - -13.7 -5.1 1996 -6.2 - - - - - - - - - - -5.2 1997 - - - - - - - - - - - - 1998 - - -28.7 -40.5 -34.2 - - - - - - - 1999 - -18.4 -32.6 -40.0 -38.9 -38.6 -32.4 -41.8 -28.9 -25.2 - - 2000 - - -23.6 -30.6 -34.3 -35.2 -32.3 -36.1 -35.9 -28.7 - - 2001 - - -30.3 -30.2 -36.6 -30.9 -31.4 -48.1 -34.5 -26.7 - - 2002 - - -21.9 -33.7 -27.5 -42.2 -43.0 -40.8 -31.0 -25.1 - - 2003 - - -27.2 -32.3 -31.0 -32.9 -33.1 -44.5 -36.4 -23.2 - - 2004 - - -30.6 -31.9 -39.1 -33.2 -48.2 -44.8 -40.3 -29.9 - - 2005 - - -27.5 -37.2 -29.9 -34.4 -32.0 -39.6 -35.1 -25.0 - - 2006 - - -28.7 -40.2 -44.5 -31.6 -41.2 -31.5 -33.0 -28.8 - - 2007 - -15.2 - - -33.0 -33.5 -35.1 -38.1 -35.2 -32.0 -16.2 -6.6 2008 -6.6 -18.6 -27.3 -33.4 -33.6 -31.2 -41.4 -49.2 - - - - 2009 - -21.9 -30.5 -27.8 -39.2 -42.2 -37.9 -41.2 -41.7 -29.3 -12.8 -7.2 2010 -9.9 -17.1 -30.7 -33.9 -39.9 -40.2 -41.7 -40.4 - - -15.0 -8.3 2011 -9.0 -17.8 -26.7 -31.3 -31.3 -32.4 - - - - - - 2012 - - - - - - - - - - - - 2013 - - - - - - - - - - - - 2014 - -15.7 -27.9 -37.9 -30.7 -40.2 -44.5 -27.8 -26.0 -21.6 -19.8 -9.9 2015 -8.5 -14.1 -26.9 -36.2 -34.1 -36.2 -41.4 -39.0 -39.0 -25.7 -16.6 -8.0 2016 -5.1 -17.3 -28.7 -35.7 -34.0 -40.8 -42.8 -37.8 -36.6 -27.1 -16.7 -8.0 2017 -8.0 -17.4 -26.8 -23.6 -25.5 -34.6 -39.3 -31.7 -41.4 -27.5 -18.7 -9.7 2018 -8.8 -17.9 -23.6 -30.9 -35.8 -33.9 -36.8 -44.5 -35.0 -22.6 -13.0 -6.2 2019 -9.1 -14.2 -27.0 -33.3 -31.1 -33.2 -33.8 -32.6 -28.7 -25.3 -15.1 -6.6 2020 -9.3 -12.8 -27.8 -33.3 -31.0 -34.7 -36.0 -36.5 -36.5 -24.6 -18.5 -8.1 2021 -8.2 -17.4 -31.2 -39.9 -35.1 -33.0 -33.9 -49.7 -36.1 -27.0 -14.9 -6.9 2022 -8.0 -14.3 -26.4 -31.3 -27.5 -36.3 -28.6 -35.1 -35.8 -28.1 -20.8 -7.3 2023 -8.9 -16.5 -29.1 -35.4 -39.4 -31.9 -45.6 -48.0 -24.3 -29.4 -17.6 -8.9 2024 -7.9 -18.4 -24.9 -29.0 -33.3 -30.9 -35.8 -35.3 -40.5 - -18.4 -