1991-2020 Degrees Fahrenheit 1 46.2 42.3 3.9 110 14 1960 2012 1999 1977 top-third 2 42.6 36.9 5.7 119 4 1978 2012 1999 1946 top-tenth 1938 3 37.6 33.6 4.0 114 9 1978 2012 1999 1998 top-tenth 4 36.7 33.2 3.5 117 5 1978 2012 1999 2000 top-tenth 5 39.0 35.1 3.9 118 4 1912 2012 1999 2000 top-tenth 6 41.7 38.5 3.2 117 5 1912 2012 1999 1932 top-tenth 7 44.9 42.6 2.3 117 5 1912,1978 2017 1999 1932 top-tenth 8 48.3 46.5 1.8 115 7 1912,1978 2017 1999 1932 top-tenth 9 51.6 49.7 1.9 116 6 1912 2012 1999 1932 top-tenth 10 53.6 52.0 1.6 113 9 1904 2017 1999 1954 top-tenth 2023 11 54.6 53.1 1.5 113 9 1918 2012,2017 1999 1954 top-tenth 2022 12 54.7 53.2 1.5 114 8 1918 2012 1999 1992 top-tenth 1942,1992 18 49.7 48.3 1.4 114 6 1905 2017 1999 1999 top-tenth 1999,2023 24 54.5 53.1 1.4 115 5 1905 2017 1999 1932 top-tenth 1932,2007,2023 36 53.9 53.1 0.8 108 10 1906 2018 1999 1956 top-tenth 1956 48 53.3 53.1 0.2 99 17 1905,1906 2019 1999 1957 top-third 1942,1955,2005,2012,2014 60 52.9 53.1 -0.2 85 29 1906 2020 1999 1992 top-third 1939,1941,1945,2005,2011,2014