1991-2020 Degrees Fahrenheit 1 27.0 17.3 9.7 75 1 1992 2003 2002 2003 highest 2 23.2 17.8 5.4 67 7 1992 1981 2002 1999 top-tenth 1995 3 25.6 22.0 3.6 64 10 1992 2018 2002 2000 top-third 2006 4 29.8 27.5 2.3 61 13 1992 2018 2002 2000 top-third 2005 5 35.1 33.3 1.8 61 13 1992 2018 2002 2000 top-third 2023 6 39.7 38.3 1.4 61 13 1992 2018 2002 2000 top-third 7 43.5 42.2 1.3 63 11 1992 2018 2002 2000 top-third 1956,2017 8 46.0 44.5 1.5 64 10 1992 2018 2002 1999 top-third 9 46.6 45.3 1.3 63 11 1992 2018 2002 1999 top-third 2021 10 46.7 45.1 1.6 70 4 1992 2018 2002 2003 top-tenth 2006 11 45.3 44.2 1.1 67 7 1992 2018 2002 2003 top-tenth 2017,2023 12 43.3 42.6 0.7 64 10 1992 2018 2002 2002 top-third 1999,2001,2002 18 41.8 41.1 0.7 59 13 1993 2018 2002 2001 top-third 24 43.3 42.5 0.8 65 7 1993 2018 2002 2002 top-tenth 2002,2012 36 43.3 42.4 0.9 63 7 1994 2018 2002 2003 top-tenth 2006,2021 48 43.2 42.3 0.9 60 8 1976 2019 2002 2002 top-third 2002 60 43.3 42.2 1.1 61 5 1976 2020,2022 2002 2003 top-tenth 2004,2006