1991-2020 Degrees Fahrenheit 1 61.3 63.6 -2.3 14 61 1974 2007 1992 1991 bottom-third 2 62.4 64.6 -2.2 9 66 1950 2011 1992 1991 bottom-third 1976 3 61.2 63.4 -2.2 10 65 1992 2011 1992 1991 bottom-third 1968,1973 4 58.7 60.6 -1.9 18 57 1950 2012 1992 1991 bottom-third 1949,1955,1986 5 55.3 57.0 -1.7 23 52 1983 2012 1991 1992 bottom-third 1951,1978,1991 6 51.7 53.4 -1.7 28 47 1975 2012 1992 1991 normal 1991,1998 7 47.1 49.3 -2.2 20 55 1979 2020 1992 1991 bottom-third 1952 8 42.7 45.3 -2.6 15 60 1984 2018 1992 1991 bottom-third 9 38.8 42.2 -3.4 10 63 1979 2018 1992 1991 bottom-third 10 37.1 41.1 -4.0 7 66 1973,1992 2018 1992 1991 bottom-tenth 11 37.9 41.3 -3.4 7 66 1992 2018 1992 1991 bottom-tenth 12 39.3 42.6 -3.3 8 65 1992 2018 1992 1991 bottom-third 18 43.4 46.1 -2.7 8 65 1984 2018 1992 1991 bottom-third 24 38.4 42.5 -4.1 1 70 1993 2018 1993 1992 lowest 36 39.3 42.5 -3.2 2 67 1975 2018 1975 1992 bottom-tenth 48 39.9 42.3 -2.4 3 64 1976 2019 1976 1992 bottom-tenth 1994 60 40.2 42.2 -2.0 4 61 1977 2020 1992 1992 bottom-tenth 1979,1992,1994