HILLSBORO, OREGON

NCDC 1961-1990 Monthly Normals

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
Mean Max. Temperature (F) 45.3 50.6 55.5 60.3 67.1 73.6 79.7 80.2 74.8 64.2 52.3 45.5 62.4
Highest Mean Max. Temperature (F) 51.8 56.5 61.1 66.8 72.2 80.6 86.5 90.3 82.1 73.0 56.7 50.7 65.1
Year Highest Occurred 1981 1968 1986 1989 1972 1961 1985 1967 1974 1987 1976 1979 1987
Lowest Mean Max. Temperature (F) 37.4 42.5 50.4 54.6 59.5 67.5 72.6 74.8 69.8 59.6 43.3 39.2 60.7
Year Lowest Occurred 1969 1989 1971 1963 1962 1980 1963 1975 1970 1984 1985 1990 1971
Mean Temperature (F) 38.9 42.6 46.0 49.6 55.1 61.4 65.8 65.8 60.7 52.4 44.6 39.4 51.9
Highest Mean Temperature (F) 43.1 47.3 50.8 54.5 58.8 66.0 69.7 71.8 64.8 57.1 48.0 44.1 53.7
Year Highest Occurred 1967 1968 1986 1989 1987 1961 1985 1967 1974 1988 1983 1979 1987
Lowest Mean Temperature (F) 30.1 34.8 42.8 45.5 51.3 57.3 61.5 61.9 56.9 49.8 36.5 33.1 50.0
Year Lowest Occurred 1979 1989 1971 1967 1962 1971 1963 1964 1970 1984 1985 1990 1985
Mean Min. Temperature (F) 32.5 34.5 36.4 38.8 43.1 49.2 51.8 51.4 46.6 40.6 36.9 33.2 41.3
Highest Mean Min. Temperature (F) 37.8 40.0 41.2 42.2 46.6 55.3 54.3 55.3 51.5 45.9 42.0 38.4 43.0
Year Highest Occurred 1967 1961 1983 1989 1987 1969 1972 1961 1990 1988 1983 1966 1961
Lowest Mean Min. Temperature (F) 22.5 27.0 32.4 34.5 39.1 44.7 49.0 47.0 42.5 37.6 29.4 25.0 38.4
Year Lowest Occurred 1979 1989 1985 1967 1964 1965 1962 1980 1965 1974 1978 1985 1985
Mean Precipitation (in.) 5.87 4.25 4.02 2.15 1.62 1.39 0.54 1.07 1.51 2.82 5.74 6.59 37.57
Highest Precipitation (in.) 11.72 10.11 8.32 4.27 3.75 4.38 2.81 3.84 3.46 5.75 12.76 11.01 51.78
Year Highest Occurred 1970 1983 1961 1982 1984 1984 1983 1968 1982 1975 1973 1968 1968
Lowest Precipitation (in.) 0.32 0.38 0.50 0.47 0.39 0.12 0.00 0.00 0.00 0.11 0.87 1.54 23.86
Year Lowest Occurred 1985 1964 1965 1966 1982 1962 1984 1986 1975 1988 1976 1976 1985
Heating Degree Days (F) 809. 627. 589. 462. 307. 137. 55. 79. 149. 391. 612. 794. 5011.
Cooling Degree Days (F) 0. 0. 0. 0. 0. 29. 80. 103. 20. 0. 0. 0. 232.

Western Regional Climate Center, wrcc@dri.edu