CASTLE ROCK, COLORADO

NCDC 1971-2000 Monthly Normals

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
Monthly
Mean Max. Temperature (F) 43.9 46.6 51.9 58.3 67.4 78.2 84.0 81.9 74.4 65.0 51.2 45.0 62.3
Highest Mean Max. Temperature (F) 55.1 54.3 61.5 66.7 73.0 84.4 87.8 87.4 80.8 69.3 62.3 54.9 87.8
Year Highest Occurred 1986 1995 1989 1981 1974 1994 2000 1995 1998 1992 1999 1980 2000
Lowest Mean Max. Temperature (F) 32.8 36.3 43.9 48.9 59.5 72.5 79.8 79.3 69.6 53.0 43.7 30.1 30.1
Year Lowest Occurred 1979 1989 1984 1983 1995 1982 1973 1987 1985 1984 1985 1983 1983
Mean Temperature (F) 28.8 32.0 37.7 44.3 53.5 62.9 68.6 66.7 58.7 48.4 36.2 29.9 47.3
Highest Mean Temperature (F) 40.9 39.5 44.7 50.7 57.3 67.7 70.7 70.8 64.1 52.5 44.5 37.6 70.8
Year Highest Occurred 1986 2000 1986 1981 1994 1994 2000 1995 1998 1988 1999 1980 1995
Lowest Mean Temperature (F) 17.4 24.3 31.3 36.6 48.4 58.2 65.3 63.9 53.1 39.8 28.0 16.6 16.6
Year Lowest Occurred 1979 1989 1984 1983 1983 1982 1973 1974 1974 1984 1972 1983 1983
Mean Min. Temperature (F) 13.6 17.4 23.4 30.2 39.5 47.6 53.1 51.4 43.0 31.8 21.2 14.8 32.3
Highest Mean Min. Temperature (F) 26.7 25.6 30.2 34.8 43.4 52.7 55.6 54.4 49.1 36.4 28.7 20.4 55.6
Year Highest Occurred 1986 2000 1986 1981 1987 1986 1998 1988 1990 1988 1998 1980 1998
Lowest Mean Min. Temperature (F) 2.0 8.4 18.5 24.2 35.1 43.0 49.6 47.6 36.6 26.6 11.8 3.1 2.0
Year Lowest Occurred 1979 1982 1998 1984 1983 1998 1972 1974 1974 1984 1972 1983 1979
Mean Precipitation (in.) 0.55 0.53 1.50 1.87 2.42 1.92 2.37 2.16 1.24 1.09 0.98 0.71 17.34
Highest Precipitation (in.) 1.34 1.95 4.42 6.58 7.32 4.62 4.92 5.49 2.93 2.87 2.62 2.34 7.32
Year Highest Occurred 1987 1984 1990 1999 1973 1995 1998 1997 1973 1987 1992 1979 1973
Lowest Precipitation (in.) 0.03 0.00 0.00 0.17 0.08 0.00 0.14 0.27 0.04 0.08 0.00 0.00 0.00
Year Lowest Occurred 1998 1991 1987 1987 1974 1980 1994 1978 1992 1988 1989 1990 1991
Heating Degree Days (F) 1123. 923. 848. 623. 362. 120. 14. 38. 214. 515. 864. 1088. 6732.
Cooling Degree Days (F) 0. 0. 0. 0. 4. 58. 123. 89. 25. 0. 0. 0. 299.

Western Regional Climate Center, wrcc@dri.edu