PORTHILL, IDAHO

NCDC 1971-2000 Monthly Normals

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
Monthly
Mean Max. Temperature (F) 33.3 38.8 48.5 59.3 68.1 74.5 81.6 81.8 71.2 56.7 41.6 33.8 57.4
Highest Mean Max. Temperature (F) 41.3 45.5 56.0 64.4 74.5 81.4 91.6 89.3 80.7 61.3 47.1 41.4 91.6
Year Highest Occurred 1994 1991 1992 1987 1993 1992 1985 1971 1998 1978 1995 1979 1985
Lowest Mean Max. Temperature (F) 22.1 29.3 41.1 53.4 60.8 67.4 71.7 74.7 63.6 52.1 30.3 25.3 22.1
Year Lowest Occurred 1979 1989 1975 1972 1996 1981 1993 1976 1986 1985 1985 1983 1979
Mean Temperature (F) 25.6 30.2 37.9 46.5 54.6 60.9 66.3 65.4 55.8 44.4 34.0 26.6 45.7
Highest Mean Temperature (F) 34.0 36.7 42.3 50.4 60.4 66.2 72.6 69.9 61.6 48.2 39.9 34.3 72.6
Year Highest Occurred 1994 1991 1992 1987 1993 1992 1985 1971 1998 1988 1999 1979 1985
Lowest Mean Temperature (F) 12.4 19.8 32.0 42.4 49.9 55.8 59.9 59.9 51.5 42.2 21.9 16.9 12.4
Year Lowest Occurred 1979 1989 1976 1975 1984 1981 1993 1980 1985 1972 1985 1983 1979
Mean Min. Temperature (F) 17.8 21.5 27.2 33.6 41.1 47.3 51.0 49.0 40.4 32.0 26.3 19.3 33.9
Highest Mean Min. Temperature (F) 26.7 28.3 32.8 37.5 46.3 51.0 56.5 53.5 44.3 35.5 34.1 27.6 56.5
Year Highest Occurred 1994 1992 1983 1994 1993 1992 1998 1999 1978 1988 1999 1999 1998
Lowest Mean Min. Temperature (F) 2.7 10.3 21.7 29.3 36.2 44.2 48.0 44.3 36.8 27.9 13.4 8.5 2.7
Year Lowest Occurred 1979 1989 1976 1999 1999 1976 1993 1980 1983 1991 1985 1983 1979
Mean Precipitation (in.) 2.13 1.69 1.52 1.43 1.92 1.85 1.34 1.21 1.24 1.41 2.76 2.41 20.91
Highest Precipitation (in.) 4.84 3.73 3.29 2.27 6.63 4.64 3.28 2.91 3.64 3.47 5.81 5.08 6.63
Year Highest Occurred 1974 1979 1997 1997 1998 1981 1986 1989 1986 1975 1973 1996 1998
Lowest Precipitation (in.) 0.25 0.27 0.37 0.32 0.67 0.28 0.12 0.04 0.02 0.04 0.46 0.42 0.02
Year Lowest Occurred 1985 1987 1981 1977 1985 1973 1973 1994 1990 1974 1979 1978 1990
Heating Degree Days (F) 1224. 976. 842. 556. 328. 156. 71. 84. 289. 640. 932. 1192. 7290.
Cooling Degree Days (F) 0. 0. 0. 0. 5. 33. 111. 97. 12. 0. 0. 0. 258.
Western Regional Climate Center, wrcc@dri.edu