1901-2000 Degrees Fahrenheit 1 21.6 10.8 10.8 126 3 1983 1939 1998 1997 top-tenth 2 28.8 18.3 10.5 128 1 1927 1999 1998 1999 highest 3 33.3 26.7 6.6 126 3 1919 2015 1998 1999 top-tenth 4 38.5 33.9 4.6 121 8 1919 2015 1998 1994 top-tenth 1939,1994 5 44.0 40.2 3.8 120 9 1985 2015 1998 1998 top-tenth 1998 6 48.2 44.9 3.3 121 8 1985 2015 1998 1953 top-tenth 1953 7 50.3 47.4 2.9 120 9 1985 2021 1998 1963 top-tenth 1923,2005 8 50.9 48.1 2.8 120 9 1927 2021 1998 1987 top-tenth 9 50.0 47.2 2.8 120 9 1927 2015 1997 1998 top-tenth 1939,2005 10 47.9 44.8 3.1 122 7 1951 2021 1998 1987 top-tenth 2001 11 45.4 41.6 3.8 123 6 1917 1987 1997 1998 top-tenth 12 42.1 38.5 3.6 120 9 1950 1987 1997 1998 top-tenth 18 44.1 40.6 3.5 120 8 1917 2016 1997 1998 top-tenth 24 42.4 38.5 3.9 126 2 1917,1951 2016 1998 1999 top-tenth 36 41.4 38.5 2.9 121 6 1918,1951 2017 1998 1988 top-tenth 48 40.0 38.5 1.5 103 23 1919 2001 1998 1991 top-third 1933,2021 60 39.7 38.4 1.3 96 29 1899 2002 1998 1992 top-third 1935,1942,1984,2022