MC NARY DAM, WASHINGTON

NCDC 1971-2000 Monthly Normals

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
Monthly
Mean Max. Temperature (F) 39.5 45.9 55.6 63.4 71.1 78.0 85.9 85.8 76.4 63.7 49.0 40.5 62.9
Highest Mean Max. Temperature (F) 47.4 51.5 59.6 68.9 75.3 84.6 93.1 91.5 83.4 70.6 54.7 47.1 93.1
Year Highest Occurred 1999 1999 1986 1987 1992 1986 1998 1986 1990 1988 1999 1974 1998
Lowest Mean Max. Temperature (F) 23.5 33.8 48.3 57.0 66.0 72.3 78.2 78.9 69.7 60.2 36.1 26.1 23.5
Year Lowest Occurred 1979 1989 1993 1975 1977 1981 1993 1976 1985 1982 1985 1985 1979
Mean Temperature (F) 34.1 38.4 45.5 52.1 59.5 66.1 73.0 73.0 64.3 53.3 42.4 35.3 53.1
Highest Mean Temperature (F) 40.8 43.2 49.4 56.1 63.1 71.8 79.4 77.6 70.2 59.2 47.6 40.9 79.4
Year Highest Occurred 1990 1999 1983 1987 1993 1992 1998 1986 1990 1988 1998 1973 1998
Lowest Mean Temperature (F) 18.4 26.3 40.6 46.6 55.6 61.9 67.4 68.3 59.6 50.6 30.3 22.9 18.4
Year Lowest Occurred 1979 1989 1993 1975 1977 1981 1993 1975 1985 1984 1985 1985 1979
Mean Min. Temperature (F) 28.6 30.8 35.4 40.8 47.8 54.1 60.1 60.1 52.2 42.8 35.8 30.0 43.2
Highest Mean Min. Temperature (F) 35.5 36.0 40.0 45.0 51.7 59.5 65.7 63.7 58.1 47.8 40.8 36.0 65.7
Year Highest Occurred 1981 1992 1983 1994 1993 1992 1998 1986 1998 1988 1998 1973 1998
Lowest Mean Min. Temperature (F) 13.4 18.8 31.6 35.4 44.5 50.4 56.6 56.5 48.3 39.8 24.5 19.6 13.4
Year Lowest Occurred 1979 1989 1976 1982 1982 1976 1993 1995 1971 1981 1985 1985 1979
Mean Precipitation (in.) 1.01 0.77 0.75 0.62 0.65 0.43 0.25 0.37 0.39 0.59 1.18 1.12 8.13
Highest Precipitation (in.) 2.28 1.77 2.06 1.89 1.61 1.22 1.00 1.62 1.79 1.93 3.23 3.61 3.61
Year Highest Occurred 1975 1983 1983 1988 1994 1984 1992 1978 1982 1982 1973 1973 1973
Lowest Precipitation (in.) 0.03 0.00 0.04 0.02 0.09 0.00 0.00 0.00 0.00 0.00 0.06 0.20 0.00
Year Lowest Occurred 1977 1988 1994 1977 1992 1986 2000 2000 1991 1988 1993 1997 1988
Heating Degree Days (F) 960. 747. 604. 388. 191. 66. 10. 11. 105. 366. 678. 924. 5050.
Cooling Degree Days (F) 0. 0. 0. 1. 17. 98. 258. 257. 83. 1. 0. 0. 715.

Western Regional Climate Center, wrcc@dri.edu