1991-2020 Degrees Fahrenheit 1 38.9 42.3 -3.4 17 79 1976 1985 2014 2018 bottom-third 2 48.0 47.5 0.5 57 39 1976 1985 2018 2017 normal 3 55.0 53.1 1.9 86 10 1976 1931 2018 2016 top-tenth 4 59.0 57.4 1.6 89 7 1976 2016 2018 2016 top-tenth 2020 5 61.9 60.2 1.7 91 5 1976 2016 2018 2016 top-tenth 6 62.8 61.4 1.4 89 7 1976 2016 2018 2016 top-tenth 7 63.1 61.3 1.8 93 3 1976 2016 2017 2018 top-tenth 8 62.1 60.1 2.0 95 1 1976 2019 2018 2019 highest 9 59.6 57.9 1.7 94 2 1997 2016 2018 2016 top-tenth 10 57.5 55.5 2.0 95 1 1958 2016,2019 2018 2016 highest 2016 11 54.9 53.2 1.7 93 3 1978,1981 2017,2020 2018 2017 top-tenth 12 53.4 51.7 1.7 91 4 1978 2016 2018 2017 top-tenth 18 56.4 54.9 1.5 90 4 1977 2017 2018 2017 top-tenth 24 52.8 51.7 1.1 90 3 1978,1979 2017 2018 2018 top-tenth 2018,2021 36 53.0 51.6 1.4 88 3 1978,1979 2018 2017 2018 top-tenth 2021 48 53.2 51.6 1.6 88 1 1981 2019,2020 2018 2019 highest 2020 60 52.9 51.5 1.4 85 2 1981 2020 2018 2019 top-tenth 2021