1991-2020 Degrees Fahrenheit 1 41.1 44.7 -3.6 14 49 2014 2012 1978 1980 bottom-third 2 39.7 40.8 -1.1 32 31 2015 2012 1980 1977 normal 3 35.7 38.7 -3.0 19 44 1978 2012 1980 1976 bottom-third 1968 4 35.4 38.6 -3.2 17 46 1978 2012 1979 1980 bottom-third 5 36.8 40.1 -3.3 10 50 1970 2012 1978 1980 bottom-third 1984 6 39.6 42.9 -3.3 6 54 1970 2012 1978 1980 bottom-tenth 7 44.1 46.7 -2.6 14 46 1970 2012 1979 1980 bottom-third 1964 8 48.2 50.3 -2.1 16 44 1970 2017 1979 1980 bottom-third 1994,1996 9 51.4 53.4 -2.0 16 44 1977 2017 1979 1980 bottom-third 10 53.1 55.3 -2.2 12 48 1977 2012,2017 1980 1980 bottom-third 1980,2001 11 54.3 56.2 -1.9 17 43 1977 2012 1980 1976 bottom-third 2001 12 54.4 56.1 -1.7 18 42 1977 2012 1980 1976 bottom-third 2014 18 50.0 51.7 -1.7 16 42 1978 2017 1980 1976 bottom-third 1994 24 54.1 56.1 -2.0 14 44 1978 2017 1980 1976 bottom-third 36 54.0 56.1 -2.1 9 47 1969,1970,1979 2022 1980 1977 bottom-third 1967 48 53.9 56.0 -2.1 8 46 1970 2023 1980 1978 bottom-third 1967,1978 60 53.6 56.0 -2.4 2 50 1970 2020 1971 1980 bottom-tenth 1971