1991-2020 Degrees Fahrenheit 1 49.6 49.5 0.1 37 49 2002 1963 1995 1998 normal 2 55.8 56.6 -0.8 40 46 1993 1963 1995 1998 normal 1982 3 60.9 61.6 -0.7 32 54 1993 1947 1993 1998 normal 4 64.9 64.8 0.1 55 31 1992 1947 1997 1998 normal 1939,1975,1982,2001 5 65.6 65.8 -0.2 43 43 1992 2021 1997 1998 normal 1960,1987,1997 6 64.8 64.8 0.0 50 36 1967 2021 1997 1998 normal 1995 7 62.7 62.2 0.5 61 25 1945,1967 1955 1997 1998 top-third 8 59.2 58.6 0.6 63 22 1965 2012,2021 1997 1998 top-third 1946,1959,2022 9 55.8 54.4 1.4 75 10 1965 2012 1997 1998 top-third 1973,2000 10 51.6 50.6 1.0 71 14 1965 2012 1997 1998 top-third 11 49.2 48.0 1.2 73 12 1965 2012 1997 1998 top-third 12 48.3 46.9 1.4 73 12 1951 2012 1997 1998 top-third 18 54.2 52.8 1.4 78 7 1951 2012 1998 1987 top-tenth 1987 24 48.7 46.9 1.8 79 5 1951 2017 1998 1988 top-tenth 1988 36 47.2 46.9 0.3 70 13 1952 2012 1998 1989 top-third 2001,2002 48 46.4 46.9 -0.5 55 27 1952 2013 1998 1991 top-third 2004 60 46.6 46.9 -0.3 55 26 1952,1969 2002,2007 1998 1991 top-third 1989