1901-2000 Degrees Fahrenheit 1 17.0 17.3 -0.3 54 76 1933 1963 2002 2004 normal 2 17.8 15.6 2.2 87 43 1949 1934 2004 2003 top-third 2021 3 18.9 15.8 3.1 104 25 1949 1934 2004 2003 top-third 1998 4 20.1 17.5 2.6 106 23 1949 1934 2004 2003 top-third 5 22.9 20.4 2.5 115 14 1949 1934 2004 2003 top-third 2003 6 25.8 23.7 2.1 109 20 1949 2015 2004 2003 top-third 1926 7 29.1 27.1 2.0 112 17 1949 2015 2004 2000 top-third 1951,1981 8 31.8 29.8 2.0 114 15 1949 2015 2004 2004 top-third 1940,1959,1998,2003,2004,2014 9 33.2 31.3 1.9 118 11 1949 2015 2004 2004 top-tenth 1998,2003,2004,2014 10 33.6 31.8 1.8 116 13 1917 2015 2004 2004 top-tenth 1995,2004 11 33.4 31.6 1.8 119 10 1917 2015 2004 1999 top-tenth 1995 12 32.9 30.8 2.1 124 5 1949 2015,2016 2004 1999 top-tenth 1999 18 30.2 28.4 1.8 118 10 1933 2016 2003 2004 top-tenth 24 32.8 30.8 2.0 123 5 1930,1933,1937 2016 2004 1935 top-tenth 1935,2019 36 32.5 30.8 1.7 121 6 1931,1933,1957 2017 2004 2005 top-tenth 2020 48 32.4 30.8 1.6 119 7 1932 2018 2004 2005 top-tenth 2021 60 32.1 30.8 1.3 112 13 1933 2018,2019 2004 1999 top-third 2023