Henry 18Z temperature 1993 - -40.1 -50.7 -56.7 -55.4 -59.2 -57.3 - - - -35.1 -25.3 1994 -25.3 -40.9 -51.8 -55.5 -57.0 -53.4 -58.3 - - - -35.0 -25.4 1995 -27.6 -38.0 -49.7 -56.3 -58.6 -55.6 -52.9 -60.3 - - -34.9 -23.4 1996 -26.4 -35.5 -54.1 -54.0 -59.1 -58.5 -53.9 -52.0 - - -32.4 -22.5 1997 -26.0 -40.0 -52.4 -55.4 -57.0 -54.7 -63.8 -58.4 - - -31.0 -23.4 1998 -24.5 -35.9 -51.5 -60.4 -56.9 -55.0 -57.2 -60.5 - - -34.2 -24.6 1999 -22.7 -38.1 -53.2 -59.0 -55.8 -56.5 -59.8 -55.6 - - -35.9 -27.0 2000 -26.5 -40.7 -53.5 -60.1 -58.0 -57.4 -59.5 -59.1 - - -30.6 -23.4 2001 -25.0 -38.1 -53.5 -57.6 -56.8 -54.8 -58.3 -61.5 - - -31.8 -22.8 2002 -23.2 -37.4 -48.0 -52.6 -53.9 -59.0 -52.8 -56.3 - - -36.1 -26.2 2003 -24.1 -36.8 -51.2 -55.9 -58.6 -61.1 -61.6 - - -49.0 -34.0 -21.1 2004 -23.4 -35.2 -52.1 -53.9 -56.9 -60.2 -65.0 - - - -35.5 -21.2 2005 -21.8 -36.8 -50.7 -53.2 -57.6 -56.6 -60.8 - - - -35.3 -20.6 2006 -24.2 -40.2 -53.6 -54.9 -55.6 -56.9 -64.0 - - - -33.4 -24.7 2007 -23.7 -38.3 -54.5 -59.3 -52.7 -51.4 -56.5 - - - -34.2 -24.2 2008 - -38.4 -50.5 -53.3 -57.5 -59.2 -54.4 -58.4 -53.5 -48.4 -34.5 -22.5 2009 -23.5 -38.5 -50.7 -57.0 -49.9 -53.1 -55.8 -59.6 -55.9 -48.5 -32.4 -22.4 2010 -22.1 -34.6 -47.8 -60.9 -51.9 -58.3 -57.7 -56.6 -59.2 -46.1 -33.7 -22.9 2011 -22.7 -34.4 -52.9 -58.1 -60.1 -59.2 -56.4 -53.8 -56.6 -45.2 -30.7 -22.3 2012 -24.7 -37.7 -50.0 -59.4 -58.3 -56.3 -60.0 -61.4 -59.5 -48.2 -32.3 -19.7 2013 -23.2 -40.2 -51.7 -56.2 -59.9 -50.3 -56.9 -51.7 -48.7 -46.4 -30.9 -21.8 2014 -23.2 -39.1 -55.3 -52.2 -53.8 -54.5 -59.5 -57.3 -57.3 -48.7 -33.7 -22.6 2015 -25.1 -39.2 -51.3 -53.4 -57.2 -56.6 -60.5 -58.7 -59.6 -45.0 -32.9 -25.8 2016 -28.1 -39.2 -51.7 -53.2 -55.5 -56.6 -60.9 -54.5 -58.8 - - - 2017 - - -50.4 -57.2 -54.8 -56.6 - - - - - - 2018 - - - - - - - - - - - - 2019 -25.9 -34.0 -49.0 -56.2 -57.1 -60.5 -57.3 -59.8 -59.0 -48.7 -33.5 -24.6 2020 -26.6 -38.8 -51.3 -52.9 -55.0 -54.0 -58.9 -61.6 -57.5 -50.8 -31.5 -24.1 2021 -26.7 -40.6 -48.8 -56.5 -55.8 -62.2 -58.0 -60.7 -58.0 -52.4 -35.9 -24.3 2022 -26.1 -37.6 -52.8 -57.2 -58.0 -52.6 -59.6 -54.8 -57.7 -49.3 -37.4 -26.6 2023 -29.2 -39.6 -49.8 -53.2 -57.0 -55.6 -57.4 -55.2 -54.5 -48.5 -36.3 - 2024 -28.9 -38.8 -52.5 -57.4 -55.1 -54.3 -52.9 -52.1 -56.8 -46.9 -35.0 -