HILLSBORO, OREGON

NCDC 1971-2000 Monthly Normals

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
Monthly
Mean Max. Temperature (F) 45.8 50.5 56.3 61.7 67.9 73.4 80.4 81.1 76.3 64.7 52.3 45.7 63.0
Highest Mean Max. Temperature (F) 51.2 57.2 63.7 68.9 75.5 78.7 87.0 87.3 82.5 73.2 60.1 53.1 87.3
Year Highest Occurred 1981 1991 1992 2000 1992 1992 1985 1986 1974 1987 1997 1999 1986
Lowest Mean Max. Temperature (F) 37.4 42.6 50.0 56.6 62.2 67.4 71.7 75.2 70.4 59.5 43.4 39.2 37.4
Year Lowest Occurred 1979 1989 1971 1975 1977 1980 1993 1975 1978 1975 1985 1990 1979
Mean Temperature (F) 40.5 43.6 47.8 51.8 57.2 62.4 67.6 67.5 62.8 53.9 45.8 40.7 53.5
Highest Mean Temperature (F) 44.7 49.1 52.5 55.8 62.0 66.6 72.3 71.4 67.3 58.2 51.0 47.5 72.3
Year Highest Occurred 1995 1992 1992 1989 1997 1992 1998 1986 1998 1988 1995 1999 1998
Lowest Mean Temperature (F) 31.5 35.9 43.4 47.0 53.1 58.0 62.8 63.6 58.9 50.9 37.5 34.1 31.5
Year Lowest Occurred 1979 1989 1971 1975 1977 1971 1993 1980 1985 1984 1985 1990 1979
Mean Min. Temperature (F) 35.1 36.7 39.3 41.8 46.4 51.4 54.7 53.9 49.3 43.0 39.2 35.6 43.9
Highest Mean Min. Temperature (F) 40.5 41.9 43.5 45.9 51.3 54.4 61.0 57.1 54.9 47.9 45.5 41.8 61.0
Year Highest Occurred 1995 1983 1983 1992 1993 1992 1998 1977 1995 1988 1998 1999 1998
Lowest Mean Min. Temperature (F) 25.7 29.3 34.7 37.4 43.9 48.3 52.2 48.9 46.0 39.8 31.4 27.2 25.7
Year Lowest Occurred 1979 1989 1985 1975 1982 1971 1984 1980 1999 1974 1978 1985 1979
Mean Precipitation (in.) 5.76 4.72 3.93 2.46 1.90 1.47 0.60 0.90 1.55 2.67 5.90 6.33 38.19
Highest Precipitation (in.) 9.66 10.31 6.93 5.03 4.77 4.38 2.81 3.03 3.46 5.75 12.76 13.78 13.78
Year Highest Occurred 1990 1999 1972 1993 1998 1984 1983 1977 1982 1975 1973 1996 1996
Lowest Precipitation (in.) 0.32 0.87 1.17 0.74 0.13 0.21 0.00 0.00 0.00 0.11 0.87 1.54 0.00
Year Lowest Occurred 1985 1993 1992 1977 1992 1986 1994 1998 1993 1988 1976 1976 1994
Heating Degree Days (F) 761. 600. 534. 398. 252. 113. 41. 38. 113. 347. 579. 756. 4532.
Cooling Degree Days (F) 0. 0. 0. 0. 9. 34. 118. 115. 47. 0. 0. 0. 323.

Western Regional Climate Center, wrcc@dri.edu