1991-2020 Degrees Fahrenheit 1 58.2 55.4 2.8 57 10 1979 1952 1989 1971 top-third 2 52.7 55.6 -2.9 10 57 1984 2022 1984 1989 bottom-third 3 56.2 58.2 -2.0 11 56 1977 2022 1988 1989 bottom-third 1956,1968,2003,2015 4 60.5 62.3 -1.8 10 57 1977 2022 1987 1989 bottom-third 1987 5 64.7 66.6 -1.9 11 56 1977 2022 1984 1989 bottom-third 6 68.6 70.4 -1.8 7 60 1977 2022 1984 1989 bottom-tenth 1984 7 71.7 73.1 -1.4 12 55 1977 2022 1988 1989 bottom-third 1972 8 73.6 75.0 -1.4 14 53 1977 2022 1988 1989 bottom-third 1969,2014 9 74.9 75.7 -0.8 22 45 1977 1999 1988 1989 bottom-third 1964,1985,1998 10 74.8 75.6 -0.8 23 43 1977 2023 1988 1989 normal 1953,1980 11 74.0 74.9 -0.9 22 44 1977 2012 1988 1989 bottom-third 1980,1987 12 72.4 73.7 -1.3 16 49 1977 2012 1988 1989 bottom-third 1980,1982 18 71.9 72.6 -0.7 27 38 1977 2023 1989 1987 normal 1975,1983 24 72.7 73.7 -1.0 22 41 1977 2013 1989 1987 normal 1994 36 71.9 73.7 -1.8 8 53 1977 2001 1979 1989 bottom-third 1973 48 72.2 73.6 -1.4 13 46 1977,1979 2002 1980 1989 bottom-third 1975 60 72.4 73.6 -1.2 16 41 1977 2003,2021,2023 1988 1989 bottom-third 1992