Henry 12Z temperature 1993 - -40.1 -50.5 -56.6 -55.5 -58.7 -57.4 - - - -36.4 -26.5 1994 -26.2 -41.2 -51.6 -56.1 -56.8 -53.1 -57.8 - - - -36.1 -26.6 1995 -28.9 -38.9 -50.4 -56.3 -58.0 -55.9 -52.9 - - - -35.8 -24.3 1996 -27.5 -36.4 -54.4 -54.1 -59.3 -58.8 -53.4 -51.4 - - -33.8 -23.9 1997 -26.8 -40.5 -52.1 -55.2 -57.4 -55.0 -63.7 -58.5 - - -32.1 -24.6 1998 -25.5 -36.3 -51.4 -60.2 -57.0 -54.9 -57.3 -60.5 - - -35.4 -25.9 1999 -24.0 -38.7 -53.2 -58.9 -56.3 -56.5 -60.0 -55.1 - - -37.2 -29.0 2000 -27.6 -41.2 -54.3 -60.1 -57.9 -57.3 -59.7 -59.0 - - -31.8 -24.7 2001 -26.2 -38.6 -53.8 -57.5 -56.7 -55.6 -58.3 -61.1 - - -32.5 -24.2 2002 -23.8 -38.3 -47.7 -51.9 -54.1 -58.9 -52.8 -55.4 - - -37.3 -27.6 2003 -25.4 -37.8 -50.9 -56.1 -58.7 -61.0 -61.7 - - -49.9 -36.0 -22.6 2004 -24.7 -36.2 -52.6 -53.7 -57.3 -60.4 -65.0 - - - -37.2 -22.7 2005 -23.7 -37.3 -50.6 -53.4 -57.9 -56.8 -60.5 - - -47.7 -36.5 -21.9 2006 -25.4 -40.8 -53.5 -54.5 -55.7 -56.8 -64.2 - - -52.5 -34.8 -26.1 2007 -24.6 -39.3 -54.6 -59.5 -52.3 -50.9 -56.4 - - - -36.0 -25.9 2008 - -39.4 -50.9 -52.9 -58.0 -59.3 -54.4 -58.6 -53.1 -49.8 -35.6 -24.4 2009 -24.9 -39.1 -50.3 -57.7 -49.5 -53.0 -56.3 -59.1 -55.4 -49.4 -33.9 -24.4 2010 -22.7 -35.1 -47.8 -60.9 -51.4 -58.1 -57.7 -56.6 -59.5 -47.3 -35.5 -24.2 2011 -23.7 -34.7 -53.1 -57.8 -60.1 -59.3 -56.0 -53.9 -56.5 -46.4 -32.0 -24.3 2012 -26.0 -38.8 -49.9 -59.2 -58.2 -56.6 -60.0 -61.3 -59.7 -48.9 -33.6 -21.9 2013 -24.1 -41.2 -52.0 -56.9 -59.9 -50.4 -57.0 -52.3 -48.5 -48.1 -32.6 -23.0 2014 -24.4 -40.1 -55.3 -52.2 -53.9 -54.2 -59.4 -57.6 -57.2 -49.5 -35.5 -24.0 2015 -26.3 -39.3 -51.7 -53.0 -57.0 -56.5 -60.7 -58.5 -59.3 -45.5 -33.1 -26.0 2016 -28.0 -39.4 -52.0 -53.6 -55.9 -55.9 -60.6 -55.0 -58.6 - - - 2017 - - - -56.9 -55.4 -56.9 - - - - - - 2018 - - - - - - - - - - - - 2019 -25.8 -34.0 -49.0 -56.6 -57.1 -60.5 -56.9 -59.9 -59.0 -49.2 -33.9 -24.7 2020 -26.5 -38.6 -51.5 -53.5 -55.3 -53.2 -59.1 -61.7 -57.8 -51.1 -32.4 -24.2 2021 -27.1 -40.6 -48.3 -56.5 -56.4 -62.2 -57.9 -60.8 -58.5 -52.1 -36.3 - 2022 -25.7 -37.7 -53.0 -57.3 -57.5 -51.8 -58.9 -55.1 -57.7 -49.2 -37.6 -26.8 2023 -29.2 -39.7 -49.5 -53.1 -57.4 -55.1 -57.5 -55.4 -54.8 -49.0 -36.4 - 2024 -28.9 -39.0 -51.9 -57.6 -54.7 -54.1 -52.3 -52.3 -57.4 -46.3 -35.0 -