1991-2020 Degrees Fahrenheit 1 63.9 66.4 -2.5 27 41 1973 2004 1982 1981 normal 2 62.0 63.3 -1.3 30 38 1964 2015 1979 1982 normal 1976 3 60.2 61.2 -1.0 36 30 1955 2015 1982 1981 normal 2005 4 58.4 59.8 -1.4 18 44 1973 2015 1977 1982 bottom-third 1971 5 58.9 60.6 -1.7 10 52 1973 2015 1977 1982 bottom-third 1956,1960,1977,1998,2019 6 61.1 63.3 -2.2 6 55 1973 2015 1975 1982 bottom-tenth 1969,1972,2001 7 64.5 66.9 -2.4 5 56 1973 2015 1977 1982 bottom-tenth 1966,1977 8 68.0 70.3 -2.3 7 54 1973 1996,2015 1977 1982 bottom-third 1958,1966 9 70.7 73.0 -2.3 7 54 1973 2015 1977 1982 bottom-third 1966,1975 10 72.0 74.6 -2.6 4 57 1973 2015 1977 1982 bottom-tenth 1977 11 72.6 75.0 -2.4 4 57 1973 2015 1973 1982 bottom-tenth 1972 12 72.5 74.8 -2.3 7 54 1966,1973 2015 1977 1982 bottom-third 1965 18 69.1 71.1 -2.0 8 48 1973 2015,2016,2018 1977 1982 bottom-third 24 73.6 74.9 -1.3 20 36 1973 2015,2016 1978 1982 normal 1968,1987 36 73.8 74.9 -1.1 22 29 1973 2017 1978 1961 normal 48 -99 74.9 -99 -99 -99 1974,1975 2018 normal 60 -99 74.8 -99 -99 -99 1973,1976 2018 normal