MOUNT VERNON 3 WNW, WASHINGTON

NCDC 1961-1990 Monthly Normals

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
Mean Max. Temperature (F) 45.2 49.3 52.8 57.2 63.5 68.6 72.9 73.9 68.5 59.7 50.6 45.4 59.0
Highest Mean Max. Temperature (F) 52.1 55.4 56.7 61.3 68.1 73.2 78.8 80.4 75.5 63.5 54.6 50.3 60.7
Year Highest Occurred 1986 1963 1987 1989 1969 1969 1985 1967 1974 1987 1965 1979 1967
Lowest Mean Max. Temperature (F) 36.7 41.3 48.6 53.9 60.0 63.8 69.1 69.0 64.1 56.2 39.0 39.1 56.9
Year Lowest Occurred 1969 1989 1976 1986 1974 1981 1986 1976 1972 1984 1985 1984 1985
Mean Temperature (F) 39.4 42.4 44.9 48.4 53.7 58.4 61.5 62.2 57.6 50.7 44.3 39.9 50.3
Highest Mean Temperature (F) 45.9 46.9 48.6 50.8 56.1 62.3 64.7 65.2 60.9 54.0 48.2 45.3 51.6
Year Highest Occurred 1986 1963 1986 1989 1969 1969 1985 1967 1963 1963 1965 1966 1987
Lowest Mean Temperature (F) 31.6 33.6 41.8 45.5 51.3 55.8 59.6 59.4 54.1 48.0 33.1 34.1 48.1
Year Lowest Occurred 1969 1989 1976 1975 1974 1971 1982 1969 1972 1972 1985 1984 1985
Mean Min. Temperature (F) 33.5 35.3 36.9 39.5 43.9 48.2 50.1 50.5 46.7 41.6 37.9 34.3 41.5
Highest Mean Min. Temperature (F) 39.6 40.3 41.2 42.5 46.1 51.4 53.1 52.8 50.5 46.3 42.9 40.6 43.2
Year Highest Occurred 1986 1961 1986 1990 1983 1969 1990 1990 1979 1967 1983 1966 1983
Lowest Mean Min. Temperature (F) 25.7 25.9 32.7 36.1 41.2 45.2 47.6 48.0 43.0 36.8 27.1 28.7 39.4
Year Lowest Occurred 1979 1989 1965 1982 1964 1965 1962 1973 1965 1987 1985 1983 1985
Mean Precipitation (in.) 4.21 2.99 2.75 2.52 2.19 1.81 1.25 1.46 2.01 2.96 4.28 4.22 32.65
Highest Precipitation (in.) 12.61 7.09 5.23 4.62 4.54 4.81 3.40 4.62 4.91 7.34 13.62 7.80 47.20
Year Highest Occurred 1974 1961 1989 1972 1988 1990 1966 1962 1964 1985 1990 1979 1990
Lowest Precipitation (in.) 0.59 1.30 0.94 1.51 0.72 0.29 0.02 0.00 0.17 0.49 1.11 0.88 20.71
Year Lowest Occurred 1985 1962 1965 1967 1972 1977 1984 1986 1989 1980 1976 1985 1987
Heating Degree Days (F) 794. 633. 623. 498. 350. 201. 117. 106. 226. 443. 621. 778. 5390.
Cooling Degree Days (F) 0. 0. 0. 0. 0. 0. 8. 19. 0. 0. 0. 0. 27.

Western Regional Climate Center, wrcc@dri.edu