1991-2020 Degrees Fahrenheit 1 -99 66.4 -99 -99 -99 1973 2004 normal 2 -99 63.3 -99 -99 -99 1964 2015 normal 3 -99 61.2 -99 -99 -99 1955 2015 normal 4 -99 59.8 -99 -99 -99 1973 2015 normal 5 -99 60.6 -99 -99 -99 1973 2015 normal 6 -99 63.3 -99 -99 -99 1973 2015 normal 7 -99 66.9 -99 -99 -99 1973 2015 normal 8 -99 70.3 -99 -99 -99 1973 1996,2015 normal 9 -99 73.0 -99 -99 -99 1973 2015 normal 10 -99 74.6 -99 -99 -99 1973 2015 normal 11 -99 75.0 -99 -99 -99 1973 2015 normal 12 -99 74.8 -99 -99 -99 1966,1973 2015 normal 18 -99 71.1 -99 -99 -99 1973 2015,2016,2018 normal 24 -99 74.9 -99 -99 -99 1973 2015,2016 normal 36 -99 74.9 -99 -99 -99 1973 2017 normal 48 -99 74.9 -99 -99 -99 1974,1975 2018 normal 60 -99 74.8 -99 -99 -99 1973,1976 2018 normal