ICE HARBOR DAM, WASHINGTON

NCDC 1961-1990 Monthly Normals

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
Mean Max. Temperature (F) 40.7 48.4 57.4 65.2 73.2 81.5 89.0 88.5 79.4 66.7 51.0 41.4 65.2
Highest Mean Max. Temperature (F) 51.3 55.5 61.6 72.0 77.5 90.7 95.1 96.5 87.1 72.9 56.3 48.1 68.7
Year Highest Occurred 1967 1967 1968 1977 1966 1961 1961 1961 1967 1988 1990 1974 1967
Lowest Mean Max. Temperature (F) 25.4 34.9 52.9 59.6 67.8 75.0 83.6 83.2 72.7 63.2 36.9 27.0 61.7
Year Lowest Occurred 1979 1989 1962 1975 1962 1971 1986 1976 1985 1969 1985 1985 1985
Mean Temperature (F) 33.7 39.3 46.0 52.7 60.1 67.8 74.1 73.9 65.0 53.8 42.7 34.6 53.6
Highest Mean Temperature (F) 43.4 45.9 49.6 57.2 64.1 74.8 79.3 79.8 72.2 58.7 47.2 41.1 56.6
Year Highest Occurred 1967 1961 1983 1987 1987 1961 1961 1967 1967 1988 1990 1974 1967
Lowest Mean Temperature (F) 18.6 27.0 42.6 48.1 56.4 63.5 69.6 70.0 60.0 51.2 29.2 22.6 50.4
Year Lowest Occurred 1979 1989 1965 1975 1977 1981 1986 1976 1985 1984 1985 1985 1985
Mean Min. Temperature (F) 26.7 30.1 34.6 40.2 47.0 53.9 59.2 59.2 50.5 40.9 34.3 27.9 42.0
Highest Mean Min. Temperature (F) 35.5 38.2 39.2 43.9 50.7 58.8 63.5 63.4 57.3 45.2 39.3 34.7 44.5
Year Highest Occurred 1967 1961 1983 1965 1987 1961 1961 1971 1967 1979 1983 1973 1967
Lowest Mean Min. Temperature (F) 11.7 19.1 30.5 34.6 43.5 48.8 55.6 55.5 46.0 36.6 21.5 18.1 39.0
Year Lowest Occurred 1979 1989 1965 1972 1978 1976 1986 1964 1983 1978 1985 1985 1985
Mean Precipitation (in.) 1.13 0.90 0.97 0.68 0.82 0.61 0.21 0.45 0.47 0.67 1.35 1.45 9.71
Highest Precipitation (in.) 3.15 1.97 2.54 2.22 2.31 1.39 0.83 2.59 1.90 2.28 3.70 4.18 14.01
Year Highest Occurred 1970 1961 1989 1978 1962 1984 1966 1978 1982 1982 1973 1964 1978
Lowest Precipitation (in.) 0.15 0.04 0.04 0.02 0.05 0.00 0.00 0.00 0.00 0.00 0.20 0.24 4.62
Year Lowest Occurred 1963 1964 1965 1973 1964 1986 1988 1988 1990 1987 1976 1965 1967
Heating Degree Days (F) 970. 720. 589. 369. 163. 46. 0. 8. 100. 347. 669. 942. 4923.
Cooling Degree Days (F) 0. 0. 0. 0. 11. 130. 287. 284. 100. 0. 0. 0. 812.

Western Regional Climate Center, wrcc@dri.edu