PORTHILL, IDAHO

NCDC 1961-1990 Monthly Normals

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
Mean Max. Temperature (F) 31.7 38.2 46.8 57.9 67.3 74.5 81.4 81.1 70.3 55.8 41.0 32.9 56.6
Highest Mean Max. Temperature (F) 38.9 42.3 52.8 63.7 71.8 81.3 90.9 89.9 81.2 60.9 45.2 40.7 59.5
Year Highest Occurred 1990 1968 1986 1987 1969 1961 1985 1967 1967 1988 1990 1979 1987
Lowest Mean Max. Temperature (F) 21.4 29.3 40.1 52.1 61.3 66.6 74.7 74.2 63.2 51.5 29.8 24.6 54.5
Year Lowest Occurred 1979 1989 1965 1970 1984 1981 1983 1976 1986 1961 1985 1983 1975
Mean Temperature (F) 24.1 29.5 36.5 45.6 53.9 60.9 65.9 64.9 55.4 43.9 33.5 26.2 45.0
Highest Mean Temperature (F) 32.7 34.7 41.5 50.1 57.4 65.3 72.2 69.5 62.7 48.2 38.8 34.0 47.3
Year Highest Occurred 1990 1983 1983 1987 1985 1961 1985 1971 1967 1988 1983 1979 1987
Lowest Mean Temperature (F) 12.1 19.8 27.5 41.6 49.6 55.5 61.9 59.7 50.2 41.2 21.6 16.6 43.0
Year Lowest Occurred 1979 1989 1965 1967 1984 1981 1986 1980 1965 1961 1985 1983 1964
Mean Min. Temperature (F) 16.4 20.6 26.1 33.2 40.4 47.3 50.5 48.6 40.4 32.0 25.9 19.3 33.4
Highest Mean Min. Temperature (F) 26.5 27.7 32.8 36.4 44.9 51.5 54.9 52.3 44.9 35.5 32.7 27.3 35.0
Year Highest Occurred 1990 1983 1983 1990 1980 1970 1975 1965 1969 1988 1983 1979 1987
Lowest Mean Min. Temperature (F) 2.7 10.3 14.8 29.4 37.3 43.6 47.1 44.3 36.1 28.7 13.4 8.5 31.2
Year Lowest Occurred 1979 1989 1965 1967 1963 1962 1962 1980 1961 1987 1985 1983 1964
Mean Precipitation (in.) 2.23 1.58 1.49 1.38 1.72 1.81 1.07 1.27 1.41 1.38 2.77 2.52 20.63
Highest Precipitation (in.) 4.84 3.73 2.91 2.22 4.34 4.64 3.28 2.91 3.64 3.47 5.81 4.46 26.06
Year Highest Occurred 1974 1979 1987 1982 1961 1981 1986 1989 1986 1975 1973 1964 1974
Lowest Precipitation (in.) 0.25 0.26 0.28 0.32 0.67 0.28 0.10 0.00 0.02 0.04 0.46 0.42 14.49
Year Lowest Occurred 1985 1964 1965 1977 1985 1973 1962 1967 1990 1974 1979 1978 1985
Heating Degree Days (F) 1268. 994. 884. 582. 344. 155. 64. 94. 300. 654. 945. 1203. 7487.
Cooling Degree Days (F) 0. 0. 0. 0. 0. 32. 92. 91. 12. 0. 0. 0. 227.

Western Regional Climate Center, wrcc@dri.edu