Boulder percent of days with non-trace snow on ground

For each month, the percent of days with >= 1 inch of snow on ground is listed. Also listed is the average (climatology) for the 1991-2020 period. All measurements have been taken at NIST/DOC since 1990.

   1948 2023
1948  -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0   0.0   0.0   9.7  20.0  25.8
1949   93.5  39.3  19.4  16.7   0.0   0.0   0.0   0.0   0.0   6.5   0.0  19.4
1950   38.7   3.6   6.5  13.3  12.9   0.0   0.0   0.0   0.0   0.0  23.3   6.5
1951   32.3  25.0  22.6  16.7   0.0   0.0   0.0   0.0   3.3   3.2  20.0  32.3
1952   29.0   3.4  32.3   3.3   0.0   0.0   0.0   0.0   0.0   3.2  36.7   0.0
1953    6.5  14.3   6.5  16.7   3.2   0.0   0.0   0.0   0.0   0.0  10.0  29.0
1954   19.4   7.1  12.9   6.7   6.5   0.0   0.0   0.0   0.0   3.2   6.7  22.6
1955   12.9  50.0  25.8   0.0   0.0   0.0   0.0   0.0   0.0   3.2  16.7  25.8
1956   16.1  51.7  22.6  10.0   0.0   0.0   0.0   0.0   0.0   3.2  30.0   9.7
1957   41.9   3.6   6.5  30.0   0.0   0.0   0.0   0.0   0.0   0.0  13.3   0.0
1958   16.1  10.7  45.2  10.0   0.0   0.0   0.0   0.0   0.0   3.2  16.7  35.5
1959   67.7  53.6  19.4  33.3   0.0   0.0   0.0   0.0   6.7  12.9  16.7   0.0
1960   58.1  44.8  41.9   3.3   0.0   0.0   0.0   0.0   0.0   0.0  10.0  54.8
1961   29.0  25.0  35.5   6.7   0.0   0.0   0.0   0.0   0.0   6.5  40.0  38.7
1962   80.6  42.9  25.8   0.0   0.0   0.0   0.0   0.0   0.0   0.0  13.3   9.7
1963   64.5  10.7  32.3   0.0   0.0   0.0   0.0   0.0   0.0   0.0   6.7  41.9
1964   22.6  31.0  22.6  10.0   0.0   0.0   0.0   0.0   0.0   0.0  23.3  22.6
1965   16.1  71.4  54.8   6.7   0.0   0.0   0.0   0.0   3.3   0.0   3.3  35.5
1966   19.4  57.1   0.0   6.7   0.0   0.0   0.0   0.0   0.0   6.5  13.3  12.9
1967   19.4  17.9   6.5   0.0   0.0   0.0   0.0   0.0   0.0   3.2  30.0  67.7
1968   48.4  24.1   6.5  13.3   0.0   0.0   0.0   0.0   0.0   0.0  16.7  22.6
1969   16.1   7.1  19.4   0.0   0.0   0.0   0.0   0.0   0.0  45.2  16.7  25.8
1970   38.7   0.0  41.9  16.7   0.0   0.0   0.0   0.0   0.0   6.5   6.7   6.5
1971   29.0  57.1  19.4   6.7   0.0   0.0   0.0   0.0  13.3  12.9   6.7  45.2
1972   32.3  13.8  12.9   0.0   0.0   0.0   0.0   0.0   0.0   6.5  53.3  74.2
1973   77.4   3.6  12.9  23.3   3.2   0.0   0.0   0.0   0.0   0.0  40.0  32.3
1974   51.6  28.6  25.8  10.0   0.0   0.0   0.0   0.0   0.0   0.0  20.0  32.3
1975   22.6  35.7  19.4  23.3   0.0   0.0   0.0   0.0   0.0   6.5  36.7  19.4
1976   29.0  13.8  32.3   0.0   0.0   0.0   0.0   0.0   0.0   3.2   3.3   9.7
1977    9.7  10.7  12.9  10.0   0.0   0.0   0.0   0.0   0.0   0.0   6.7   3.2
1978   45.2  35.7   9.7   6.7 -99.0   0.0   0.0   0.0   0.0   0.0   6.7  66.7
1979   19.4   7.1  19.4  16.7 -99.0 -99.0   0.0   0.0 -99.0   0.0 -99.0 -99.0
1980  100.0 -99.0 -99.0 -99.0   0.0   0.0 -99.0   0.0   0.0   0.0   0.0   0.0
1981    0.0 -99.0 -99.0   0.0   0.0   0.0   0.0   0.0   0.0 -99.0   0.0   0.0
1982  -99.0 -99.0   0.0   0.0   0.0   0.0   0.0 -99.0   0.0   0.0 -99.0 -99.0
1983   15.4  14.3  45.2  26.7   0.0   0.0   0.0   0.0   0.0   0.0  36.7  80.6
1984   54.8  13.8  35.5   6.7   0.0   0.0   0.0   0.0   3.3  16.1   0.0  16.1
1985   64.5  60.7  16.1   3.3   0.0   0.0   0.0   0.0  10.0   6.5  63.3  48.4
1986    6.5  35.7   0.0  10.0   0.0   0.0   0.0   0.0   0.0   6.5  26.7  93.5
1987   48.4  39.3  38.7  13.3   0.0   0.0   0.0   0.0   0.0   0.0  33.3  64.5
1988  100.0  37.9  16.1   6.7   0.0   0.0   0.0   0.0   0.0   0.0  23.3  77.4
1989   54.8  85.7  13.8  13.3   0.0   0.0   0.0 -99.0 -99.0 -99.0 -99.0 -99.0
1990  -99.0 -99.0 -99.0   3.3   0.0   0.0   0.0   0.0   0.0   3.2  30.0  45.2
1991   67.7  14.3   0.0  10.0   0.0   0.0   0.0   0.0   0.0  12.9  56.7  12.9
1992   48.4   0.0  22.6   0.0   0.0   0.0   0.0   0.0   0.0   0.0  43.3 100.0
1993   64.5  32.1   9.7   0.0   0.0   0.0   0.0   0.0   0.0  12.9  53.3  45.2
1994   19.4  75.0  16.1  20.0   0.0   0.0   0.0   0.0   0.0   0.0  53.3   9.7
1995   35.5  35.7  16.1  13.3   0.0   0.0   0.0   0.0   3.3   3.2  23.3  16.1
1996   74.2  31.0  19.4   3.6   0.0   0.0   0.0   0.0   0.0   0.0  26.7  38.7
1997   32.3  50.0  19.4  26.7   0.0   0.0   0.0   0.0   0.0  19.4  46.7  45.2
1998   67.7   3.6  29.0  13.3   0.0   0.0   0.0   0.0   0.0   0.0  16.7  58.1
1999   22.6 -99.0 -99.0 -99.0   0.0   0.0   0.0   0.0   0.0   6.5 -99.0 -99.0
2000  -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0   0.0   3.3   0.0  36.7  25.8
2001   41.9  39.3  19.4   0.0   0.0   0.0   0.0   0.0   0.0   0.0  20.0   9.7
2002   32.3  25.0  25.8   0.0   0.0   0.0   0.0   0.0   0.0  12.9  33.3   0.0
2003    0.0  64.3  45.2   3.3   0.0   0.0   0.0   0.0   0.0   0.0  13.3  41.9
2004   32.3  62.1   6.5   3.3   0.0   0.0   0.0   0.0   0.0   0.0  23.3  41.9
2005   35.5  17.9  12.9  13.3   3.2   0.0   0.0   0.0   0.0   0.0   3.3  32.3
2006   19.4  32.1  32.3   0.0   0.0   0.0   0.0   0.0   0.0  12.9   6.7  71.0
2007  100.0  64.3  12.9   0.0   0.0   0.0   0.0   0.0   0.0   0.0  13.3  80.6
2008   38.7  17.2   9.7   3.3   0.0   0.0   0.0   0.0   0.0   0.0   0.0  71.0
2009   22.6   0.0  16.1  20.0   0.0   0.0   0.0   0.0   0.0  22.6  16.7  80.6
2010   61.3  64.3  32.3   0.0   3.2   0.0   0.0   0.0   0.0   0.0   0.0   9.7
2011   61.3  50.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0  12.9  10.0 100.0
2012   29.0  72.4   0.0   3.3   0.0   0.0   0.0   0.0   0.0   9.7   3.3  29.0
2013   32.3  35.7  29.0  33.3   6.5   0.0   0.0   0.0   0.0   0.0  13.3  38.7
2014   38.7  42.9  16.1   6.7   6.5   0.0   0.0   0.0   0.0   0.0  40.0  32.3
2015   48.4  60.7  29.0   6.7   0.0   0.0   0.0   0.0   0.0   0.0  16.7  77.4
2016   61.3  41.4  32.3  10.0   0.0   0.0   0.0   0.0   0.0   0.0   6.7  22.6
2017   25.8  25.0   0.0  10.0   6.5   0.0   0.0   0.0   0.0   6.5   6.7  29.0
2018   35.5  42.9   3.2   3.3   0.0   0.0   0.0   0.0   0.0   6.5  23.3  16.1
2019   58.1  39.3  22.6  13.3   3.2   0.0   0.0   0.0   0.0  22.6  46.7  51.6
2020    0.0  82.8  16.1  26.7   0.0   0.0   0.0   0.0   6.7  12.9  23.3  35.5
2021   16.1  50.0  32.3  23.3   0.0   0.0   0.0   0.0   0.0   0.0   0.0   6.5
2022   93.5  96.4  19.4   0.0   6.5   0.0   0.0   0.0   0.0   0.0  43.3  29.0
2023   87.1  39.3   3.2 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0
  -99
 percent days with above T snow on ground Boulder CO
 
1991-2020 Climatology of Percent of Days with snow on the ground.
JanFebMarAprMayJunJulAugSepOctNovDec
41.6 40.0 17.6 8.7 1.0 0.0 0.0 0.0 0.4 5.8 23.3 42.2