WILMINGTON PORTER RSVR, DELAWARE

NCDC 1961-1990 Monthly Normals

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
Mean Max. Temperature (F) 37.8 40.8 50.9 61.4 71.9 80.5 84.6 83.0 76.2 65.2 54.3 42.9 62.5
Highest Mean Max. Temperature (F) 47.9 51.4 56.8 66.2 76.5 84.1 89.6 86.8 80.6 70.5 60.8 50.1 65.5
Year Highest Occurred 1990 1976 1977 1985 1986 1984 1988 1983 1980 1963 1975 1984 1990
Lowest Mean Max. Temperature (F) 28.0 29.9 43.5 55.9 64.4 75.5 81.0 79.8 71.8 60.1 48.3 31.8 60.6
Year Lowest Occurred 1977 1979 1984 1966 1967 1972 1962 1967 1962 1988 1976 1989 1962
Mean Temperature (F) 30.1 32.7 41.8 51.5 61.9 70.8 75.2 73.8 66.8 55.6 45.7 35.3 53.4
Highest Mean Temperature (F) 40.3 41.1 47.9 54.8 66.6 74.4 79.6 77.7 71.9 61.6 51.1 42.5 56.8
Year Highest Occurred 1990 1990 1977 1977 1982 1987 1988 1988 1961 1984 1975 1984 1990
Lowest Mean Temperature (F) 20.2 22.2 35.4 46.7 55.1 66.6 71.6 70.6 62.5 51.2 39.0 24.7 51.6
Year Lowest Occurred 1977 1979 1984 1975 1967 1972 1962 1976 1963 1988 1976 1989 1978
Mean Min. Temperature (F) 22.3 24.5 32.6 41.5 51.9 61.1 65.9 64.6 57.3 45.9 37.2 27.6 44.4
Highest Mean Min. Temperature (F) 32.7 31.8 38.9 45.7 57.8 65.5 69.6 68.8 63.2 53.1 42.9 34.9 48.0
Year Highest Occurred 1990 1990 1977 1980 1982 1989 1988 1988 1961 1984 1985 1984 1990
Lowest Mean Min. Temperature (F) 12.3 14.5 27.2 36.7 45.7 56.5 62.1 58.6 51.7 41.3 29.7 17.5 41.5
Year Lowest Occurred 1977 1979 1984 1975 1967 1965 1976 1976 1976 1972 1976 1989 1976
Mean Precipitation (in.) 3.47 3.05 3.81 4.01 4.33 4.06 4.39 4.05 3.95 3.30 3.80 3.84 46.06
Highest Precipitation (in.) 8.45 7.02 7.55 8.10 8.23 10.15 14.86 12.41 11.16 6.46 9.29 9.99 60.35
Year Highest Occurred 1979 1979 1983 1983 1978 1975 1989 1967 1971 1976 1977 1983 1983
Lowest Precipitation (in.) 0.86 0.79 1.08 0.55 0.39 0.32 1.09 0.41 1.10 0.13 0.34 0.68 33.60
Year Lowest Occurred 1981 1980 1966 1985 1964 1988 1983 1968 1972 1963 1976 1980 1968
Heating Degree Days (F) 1082. 904. 719. 405. 141. 8. 0. 0. 48. 303. 579. 921. 5110.
Cooling Degree Days (F) 0. 0. 0. 0. 45. 182. 316. 273. 102. 12. 0. 0. 930.

Southeast Regional Climate Center, sercc@climate.ncsu.edu