STATION:  CHEYENNE AIRPORT (KCYS), WY

CLIMATOLOGICAL SUMMARY.  Period of Record: Jul 1996 to Dec 2008

Summaries based on unedited daily ASOS data.  Errors may be present.

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TEMPERATURE (F)     |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Avg Max Temp        |  39.7  40.7  48.3  54.8  65.7  76.0  85.6  81.4  72.0  59.3  47.4  38.9 |   59.1
Avg Min Temp        |  18.3  18.8  24.2  30.6  40.0  48.6  56.7  54.1  44.9  34.0  24.9  18.1 |   34.4
Avg Temperature     |  29.0  29.8  36.3  42.7  52.8  62.3  71.2  67.8  58.4  46.6  36.1  28.5 |   46.8
                    |                                                                         |
Extremes:           |                                                                         |
    Extreme Max Temp|    66    67    74    80    91    97    98    98    92    82    75    66 |     98
                    |                                                                         |
    Date of Ext-Day |    20    23    31    29    29    25    31    01    05    01    15    01 |
               -Year|  2005  2002  2004  2007  2000  2007  2002  2008  1998  2005  1999  1998 |
                    |                                                                         |
    Extreme Min Temp|   -14   -19   -11     0    19    31    40    40    23     8    -3   -20 |    -20
                    |                                                                         |
    Date of Ext-Day |    12    17    02    12    03    08    04    28    27    30    11    07 |
               -Year|  1997  2006  2002  1997  2008  2007  1997  2004  1996  2002  2000  2005 |
                    |                                                                         |
Heating Degree Days |  1116   996   891   670   382   135    11    35   222   570   867  1133 |   7027
Cooling Degree Days |     0     0     0     0     5    54   202   121    25     0     0     0 |    408
                    |                                                                         |
Avg Number of Days: |                                                                         |
    Max Temp >= 90  |   0.0   0.0   0.0   0.0   0.2   2.3  10.5   3.5   0.5   0.0   0.0   0.0 |   17.1
    Max Temp >= 75  |   0.0   0.0   0.0   0.9   6.8  17.7  28.9  25.9  14.0   3.6   0.1   0.0 |   97.9
    Max Temp <= 32  |   7.7   6.3   4.2   1.8   0.0   0.0   0.0   0.0   0.1   0.8   4.6   9.1 |   34.5
                    |                                                                         |
    Min Temp <= 32  |  28.6  26.9  26.0  17.0   5.2   0.2   0.0   0.0   1.2  12.3  23.6  28.5 |  169.5
    Min Temp <= 20  |  17.2  15.1   8.9   3.0   0.2   0.0   0.0   0.0   0.0   1.4   9.0  17.5 |   72.4
    Min Temp  <= 0  |   2.0   1.3   0.3   0.1   0.0   0.0   0.0   0.0   0.0   0.0   0.5   2.2 |    6.4
                    |                                                                         |
Avg Dew Point Temp  |  13.1  13.9  18.6  24.5  33.9  40.8  45.8  46.1  37.7  27.8  18.0  13.0 |   27.8
Avg Wet Bulb Temp   |  23.7  24.1  29.3  34.9  43.5  50.7  56.5  54.8  47.5  37.8  28.9  23.3 |   37.9
                    |                                                                         |
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                    |                                                                         |
Avg Sea Level Pres  | 30.08 30.08 30.04 30.06 29.97 29.92 29.93 29.95 29.96 30.03 30.09 30.09 |  30.02
(Inches of Mercury) |                                                                         |
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                    |                                                                         |
WEATHER             |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
See disclaimer below|                                                                         |
                    |                                                                         |
Avg Number of Days: |                                                                         |
    Thunderstorms   |   0.0   0.1   0.3   1.9   6.4   9.7  10.2   9.0   4.1   0.6   0.2   0.0 |   42.6
    Heavy Fog       |   1.7   3.1   4.3   4.2   2.0   1.6   0.8   0.9   1.5   2.2   2.3   1.8 |   26.5
    Fog             |   8.2   9.5  12.2  10.4   9.9   7.1   5.2   5.6   6.5   7.1   7.0   7.2 |   95.8
    Hail            |   0.0   0.0   0.0   0.8   0.8   1.2   0.8   0.8   0.3   0.1   0.0   0.0 |    4.8
                    |                                                                         |
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                    |                                                                         |
PRECIPITATION (In)  |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Average Monthly     |  0.18  0.23  0.72  1.51  1.65  1.86  2.07  1.86  1.56  0.72  0.28  0.33 |  12.99
                    |                                                                         |
Maximum Daily       |  0.17  0.33  0.51  1.62  0.95  1.45  1.92  2.07  1.42  0.96  0.33  0.52 |   2.07
                    |                                                                         |
    Date of Ext-Day |    16    28    24    30    17    12    03    15    19    13    15    07 |
               -Year|  2001  2002  2007  1999  2000  2005  2006  2008  1997  2007  1996  2007 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
    >= 0.01         |   3.7   4.5   7.7   9.5  12.2  11.5   9.5  10.7   7.8   6.2   4.3   4.6 |   92.3
    >= 0.10         |   0.6   0.7   2.3   3.4   4.6   4.3   4.9   4.3   3.8   2.3   0.9   1.4 |   33.6
    >= 0.25         |   0.0   0.1   0.7   1.8   2.5   2.3   2.4   1.9   1.9   0.8   0.2   0.1 |   14.7
    >= 0.50         |   0.0   0.0   0.1   0.8   0.8   0.8   1.2   0.9   1.1   0.1   0.0   0.1 |    5.9
    >= 1.00         |   0.0   0.0   0.0   0.3   0.0   0.4   0.5   0.3   0.2   0.0   0.0   0.0 |    1.7
                    |                                                                         |
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                    |                                                                         |
WIND (MPH)          |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Daily Avg Wind Speed|  13.9  13.6  13.6  13.1  12.0  11.1   9.8   9.9  10.3  11.6  12.9  14.2 |   12.1
Daily Avg Max 2-Min |  28.9  27.9  27.8  27.1  26.6  26.0  24.1  24.1  23.3  24.4  27.1  29.4 |   26.4
Daily Avg Peak Gust |  35.3  34.3  34.3  33.7  33.3  32.7  30.3  30.0  29.1  30.1  33.3  36.3 |   32.7
                    |                                                                         |
Maximum Daily Avg   |  26.7  32.2  33.5  31.4  28.4  24.2  22.0  19.0  20.6  24.6  31.7  32.6 |   33.5
                    |                                                                         |
Maximum 2-Minute Avg|    55    59    59    55    54    52    46    49    48    53    59    63 |     63
                    |                                                                         |
Date of Max 2min-Day|    11    02    06    08    17    11    28    20    05    23    26    28 |
               -Year|  2000  1999  2004  1999  2005  2008  2001  1996  2000  2001  1999  1998 |
                    |                                                                         |
Maximum Peak Gust   |    69    71    69    69    67    66    59    60    60    63    68    75 |     75
                    |                                                                         |
Date of Max Gust-Day|    30    02    06    08    02    06    31    20    08    23    26    28 |
               -Year|  2003  1999  2004  1999  2008  2005  1996  1996  2000  2001  1999  1998 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
   Peak Gust >=30   |  20.2  17.1  19.6  18.1  20.1  18.2  14.8  14.1  13.1  13.6  17.7  21.2 |  207.8
   Peak Gust >=40   |  11.1   8.7   9.0   8.4   6.4   5.9   3.4   3.5   3.5   4.7   7.7  12.2 |   84.6
   Peak Gust >=50   |   3.9   3.5   2.7   1.5   1.4   1.6   0.6   0.4   0.4   1.0   2.6   4.2 |   23.8
                    |                                                                         |
   Max 2-Minute >=30|  14.2  10.6  12.9  11.1   9.2   7.2   5.6   5.6   5.4   7.1  10.6   0.0 |   99.5
   Max 2-Minute >=40|   5.1   3.6   2.9   2.0   1.4   1.6   0.5   0.5   0.4   0.9   3.0   0.0 |   21.9
                    |                                                                         |
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Observations of WEATHER may me innacurate due to early ASOS inconsistancies.  Average days
with Thunderstorms may be low due to early mis-detection.

Heavy Fog = Visibility less than or equal to 1/4 mile.
Fog = Visibility greater than 1/4 mile or less than 7 miles.
Peak Gust = Maximum 5-second average.
Snowfall data not observed at ASOS stations.

Copyright ©2009 Western Regional Climate Center - Desert Research Institute - Reno, Nevada.