Priestley_Gl temperature 1987 - - -21.8 - - - - - - -21.6 -16.2 -7.5 1988 -7.7 -14.3 - - - - - - - - - -8.6 1989 -8.4 -15.4 -23.0 -24.9 -30.3 -34.6 -29.1 -32.6 -26.4 -24.1 -15.2 -7.2 1990 -8.1 -15.4 -23.2 -29.2 -27.7 -29.8 -23.9 -31.9 -29.3 -23.7 -13.4 -6.8 1991 -8.1 -12.7 -23.4 -25.3 -28.6 -25.5 -29.8 -28.0 -27.3 - - -6.0 1992 -8.3 -14.0 -21.8 -28.6 -27.8 -26.7 -27.9 -23.6 -31.6 -24.4 - - 1993 - -14.8 -21.9 -28.2 -31.7 -30.3 -29.3 -30.6 -26.7 -23.5 -14.9 -8.7 1994 -7.5 -16.0 -26.2 -25.4 -31.6 -30.4 -27.0 - - - - -9.1 1995 -9.2 -13.5 -21.4 -25.1 -28.8 -29.5 -29.0 -27.4 -28.3 -24.2 -15.5 - 1996 -8.5 -13.6 -19.5 -24.6 -30.9 -30.9 -30.0 -26.1 -29.7 -26.1 - -7.3 1997 -8.2 -15.0 -22.6 -29.9 -31.9 - - - - - - -9.6 1998 -10.5 -14.4 -25.7 -28.8 -29.5 -29.0 -32.0 -29.9 -29.5 -23.7 - -8.3 1999 -7.7 -14.4 -23.5 -28.6 -31.3 - - - - - -13.6 -9.0 2000 -9.3 -15.3 -23.4 -29.4 -27.7 -29.5 -29.1 -30.3 -24.1 - - -8.7 2001 -8.4 -13.7 -23.1 -27.7 -29.6 -28.7 -30.3 -30.9 -29.2 -24.4 -15.0 -7.4 2002 -5.5 -14.7 -21.1 -29.1 -26.9 -25.5 -30.8 -34.7 -26.7 -22.5 -15.0 -8.6 2003 -6.4 -14.3 -24.2 -28.7 -27.5 -29.8 - - - - -14.9 -7.2 2004 -7.7 -13.2 -21.9 -27.8 -30.9 -24.5 -34.3 -28.7 -27.9 -24.0 -14.2 -5.5 2005 -7.3 -14.3 -22.0 -29.3 -29.2 -27.6 - - - - -13.5 -5.5 2006 -6.9 -13.6 -23.1 -27.6 -29.1 -28.9 -31.7 -29.3 -29.0 - - -10.4 2007 -7.2 -16.6 -23.3 -28.6 -28.1 -30.9 -31.6 -34.5 -32.0 -24.3 -16.2 -9.4 2008 - - - - - - - - - - - -8.6 2009 -8.5 -16.7 -25.6 -30.9 -29.7 -31.1 -28.2 - - - - -8.7 2010 -7.4 -14.7 -21.3 -30.8 -32.5 -35.2 -36.6 -32.3 -33.4 -25.7 - - 2011 - - - - - - - - - - - -7.9 2012 -8.5 - - - - - - - - - - -7.7 2013 -8.7 -17.6 -24.8 -32.0 -30.9 -31.8 - - - -25.0 -17.5 -7.8 2014 - - - - - - - - - - - -9.9 2015 -9.3 -15.6 -24.0 -31.5 -31.0 -33.1 - - - -24.4 -18.3 -8.8 2016 -9.2 -16.6 -25.6 -32.8 -28.6 -33.0 - - - -26.6 -13.5 -9.2 2017 -8.9 -15.3 -24.0 -31.0 -31.3 -33.2 - - - -23.6 -16.2 -10.0 2018 -9.2 -16.2 -23.6 -26.8 -33.7 -32.7 - - - -23.9 -16.2 -9.7 2019 -10.2 -16.5 -23.3 -30.4 -30.2 -33.8 - - - -26.7 -14.3 -8.7 2020 -8.4 -13.5 -24.0 -30.0 -32.5 -33.6 - - - -28.4 -18.2 -8.8 2021 -9.2 -16.8 -24.4 -31.8 -35.9 - - - - -24.7 -16.8 -9.2 2022 -10.1 -15.1 -22.4 -30.4 -30.7 -28.9 - - -31.9 - - - 2023 -10.1 -15.9 -23.7 -27.9 -32.1 -30.9 -31.0 -34.1 -29.4 -28.6 -17.4 -9.7 2024 -10.2 -17.4 -26.0 -31.9 -33.1 -33.4 -29.5 -30.6 -30.0 -25.6 -18.5 -8.4 2025 -8.0 -15.2 -25.2 -30.1 -30.8 -28.0 -29.9 -31.6 -29.4 -23.2 - - 2026 - - - - - - - - - - - -