1991-2020 Degrees Fahrenheit 1 49.7 44.0 5.7 74 1 1969 2015 2013 2015 highest 2 54.3 50.0 4.3 74 1 1970 2015 2013 2015 highest 3 57.7 54.5 3.2 74 1 1976 2015 2013 2015 highest 4 59.4 57.3 2.1 74 1 1976 2015 2013 2015 highest 5 60.2 58.0 2.2 74 1 1976 2015 2013 2015 highest 6 58.6 57.0 1.6 74 1 1971,1975,1976 2015,2018 2013 2015 highest 2018 7 56.5 55.0 1.5 73 2 1975 2018 2013 2012 top-tenth 2012 8 54.4 52.5 1.9 74 1 1970 2015 2013 2015 highest 9 51.6 49.4 2.2 74 1 1973,1984 2015 2013 2015 highest 10 48.7 46.2 2.5 74 1 1984 2015 2013 2015 highest 11 -99 43.6 -99 -99 -99 1979,1984 2018 normal 12 -99 42.5 -99 -99 -99 1973 2018 normal 18 -99 47.3 -99 -99 -99 1973 2018 normal 24 -99 42.5 -99 -99 -99 1993 2018 normal 36 -99 42.4 -99 -99 -99 1975 2018 normal 48 -99 42.3 -99 -99 -99 1976 2019,2020 normal 60 -99 42.2 -99 -99 -99 1977 2020,2021 normal