D_10 18Z temperature 1980 - -7.9 -9.8 -15.0 -17.2 -18.3 -14.3 -18.0 -14.2 -19.1 -10.1 -5.7 1981 - -7.8 -12.2 -13.8 - - - - - - - - 1982 - - -14.1 -17.6 -13.7 -14.7 -17.2 -24.8 -21.0 - - - 1983 -3.9 -6.8 -14.4 -16.6 -15.8 -15.9 -22.7 -20.7 -16.3 -20.3 -12.7 - 1984 - -8.0 -9.6 -16.4 -13.7 -20.3 -19.9 -15.3 -16.5 -16.8 -12.4 -4.0 1985 - -8.5 -13.1 -17.4 - -18.6 -20.2 -17.1 -20.6 -18.1 -13.1 -7.7 1986 -6.1 -5.6 -9.8 - -19.0 -19.0 -19.4 -15.8 - - - -7.3 1987 -4.0 -8.0 -12.9 -16.7 -19.4 -13.7 -18.7 -20.9 -17.8 - - -6.7 1988 -5.0 -9.9 -15.6 -14.8 -18.6 -19.8 -19.1 -20.4 -17.3 -15.2 -12.9 -6.8 1989 -8.6 -10.1 -15.1 -14.8 -18.3 -23.2 -17.1 -18.5 -14.7 -15.6 -13.4 -5.2 1990 -5.3 -10.5 -15.2 -16.2 -16.9 -20.4 -12.7 -20.0 -20.2 - - - 1991 - - -12.3 -12.9 -17.9 -13.2 -19.4 -14.0 -17.6 -16.3 -9.9 -3.6 1992 -4.8 -7.5 -11.2 -14.1 -18.3 -14.2 -17.5 -12.8 -19.0 -19.4 -10.1 -7.6 1993 -2.5 -8.1 - - - - - - - -16.4 -10.6 -5.6 1994 -5.6 -9.9 -13.7 -16.3 -21.8 - - - - -15.5 -11.3 -6.7 1995 -7.1 -9.0 -10.8 -13.3 -17.6 - - - - - - - 1996 - - - - - - - - - - - - 1997 - - - - - - - - - - - - 1998 - -7.3 -14.0 -17.3 -17.4 -19.3 - - -18.5 - - - 1999 -8.6 -10.4 -15.5 -18.8 -20.4 - - - -20.1 -16.0 -11.8 -8.7 2000 -8.7 -10.3 -13.5 -20.1 -17.0 -19.0 - - - - - -5.9 2001 -4.1 -9.6 -11.8 -17.3 -16.3 -17.1 - - - -15.5 -12.5 -6.1 2002 -4.7 -8.5 -11.7 -16.4 -16.3 -14.7 - - -18.0 -17.3 -11.2 -6.0 2003 -4.7 - - - - - - -18.9 -17.6 -18.4 -12.7 -5.5 2004 -3.9 -7.5 -12.7 - - -14.4 - - - - - - 2005 - - - - - - - - -17.9 -14.4 - - 2006 - - - - - - - - - - - - 2007 - - - - - - - - - - - - 2008 - - -16.0 -16.4 -17.2 -20.6 -21.0 -17.1 -19.1 -19.4 -10.6 -6.4 2009 -5.7 -9.6 -15.1 -18.6 -17.4 -18.0 -14.3 -17.5 -17.4 -19.0 -12.2 -6.5 2010 -2.5 -9.6 -13.7 -18.9 -18.6 -20.7 -21.8 -18.8 -23.8 -16.4 -11.5 -5.5 2011 -4.7 -11.6 -14.1 -15.7 -20.2 -18.5 -21.5 -19.0 -18.2 -17.4 -11.2 -6.0 2012 -6.8 -10.5 -14.5 -18.8 -17.8 -19.3 -21.3 -17.7 -20.6 -18.4 -11.5 -6.0 2013 -5.3 -11.4 -15.2 -19.8 -18.4 -19.8 -23.5 -18.9 -15.1 -17.0 - - 2014 - -9.4 -14.2 - - - - - - - - - 2015 - - - - - - - - - - - - 2016 - - - - - - - - - - - - 2017 - - - - - - - - - - - - 2018 -5.2 -8.9 -14.2 -11.9 -20.1 -21.5 -17.8 -19.2 -20.2 -17.9 -11.7 -6.8 2019 -6.4 -9.3 -13.9 -19.6 -22.6 -23.6 -18.3 -21.6 -21.7 -17.9 -9.9 - 2020 -4.7 -9.2 -15.3 -13.4 -18.5 -20.0 -15.7 -20.7 -19.1 -17.8 -11.7 -5.4 2021 -5.9 -10.8 -14.0 -19.1 -20.6 -18.9 -20.1 -15.7 -18.6 -14.2 -12.1 -7.4 2022 -7.3 -8.6 -11.9 -17.2 -17.3 -18.4 -17.2 -20.3 -16.9 -15.1 -11.8 -6.9 2023 -7.4 -8.2 -11.2 -14.2 -18.8 -17.3 -19.3 - - - - - 2024 - - - - - - - - - - - -