1991-2020 Degrees Fahrenheit 1 12.2 22.0 -9.8 8 78 1983 2015 1963 1971 bottom-tenth 2 22.7 28.4 -5.7 12 74 1985 2001 1955 1971 bottom-third 1977 3 30.1 35.5 -5.4 6 80 1985 2015 1955 1971 bottom-tenth 4 37.3 42.5 -5.2 4 82 1985 2015 1951 1971 bottom-tenth 5 44.0 48.4 -4.4 4 82 1985 2015 1951 1971 bottom-tenth 6 48.2 52.7 -4.5 3 83 1985 2011 1951 1971 bottom-tenth 7 50.9 55.1 -4.2 3 83 1985 2021 1951 1971 bottom-tenth 8 52.3 55.7 -3.4 4 82 1945 2021 1951 1971 bottom-tenth 9 51.3 54.7 -3.4 4 82 1945 2021 1951 1971 bottom-tenth 10 48.9 52.6 -3.7 3 82 1951 2021 1951 1971 bottom-tenth 11 45.5 49.7 -4.2 3 82 1951 2012 1951 1971 bottom-tenth 12 42.2 46.9 -4.7 2 83 1950 2012 1951 1971 bottom-tenth 1951 18 45.3 48.8 -3.5 2 83 1951 2012 1951 1971 bottom-tenth 24 43.4 46.9 -3.5 2 82 1951 1999,2012,2017 1951 1971 bottom-tenth 36 43.8 46.9 -3.1 4 79 1952 2012,2017 1967 1971 bottom-tenth 48 44.0 46.9 -2.9 1 81 1972 2018 1972 1971 lowest 60 44.4 46.9 -2.5 1 80 1969,1972 2002 1969 1971 lowest 1969