STATION:  ROCK SRINGS-SWETWTER CO APT (KRKS), 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        |  29.9  32.2  43.6  54.0  64.8  74.9  85.6  81.9  69.5  57.3  42.4  30.3 |   55.5
Avg Min Temp        |  13.4  14.6  23.1  29.1  38.0  46.1  55.4  53.0  42.6  33.1  22.8  13.4 |   32.1
Avg Temperature     |  21.7  23.4  33.4  41.5  51.4  60.5  70.5  67.4  56.0  45.2  32.6  21.9 |   43.8
                    |                                                                         |
Extremes:           |                                                                         |
    Extreme Max Temp|    53    58    71    79    90    93    98    96    87    85    64    53 |     98
                    |                                                                         |
    Date of Ext-Day |    31    01    22    29    31    30    13    14    04    28    04    01 |
               -Year|  2003  2003  2004  2007  2002  2001  2002  2003  1998  2007  1999  1998 |
                    |                                                                         |
    Extreme Min Temp|   -17   -22    -6    10    21    28    40    36    18     8    -2   -20 |    -22
                    |                                                                         |
    Date of Ext-Day |    14    09    02    01    08    13    02    27    27    30    29    08 |
               -Year|  2007  2001  2002  2008  2002  2001  1997  2004  1996  2002  2006  2005 |
                    |                                                                         |
Heating Degree Days |  1343  1174   981   704   426   171     8    30   279   613   972  1337 |   8038
Cooling Degree Days |     0     0     0     0     4    37   179   105    10     0     0     0 |    334
                    |                                                                         |
Avg Number of Days: |                                                                         |
    Max Temp >= 90  |   0.0   0.0   0.0   0.0   0.1   1.1   8.4   2.4   0.0   0.0   0.0   0.0 |   12.0
    Max Temp >= 75  |   0.0   0.0   0.0   0.3   6.2  17.7  29.8  27.7  11.1   1.3   0.0   0.0 |   94.1
    Max Temp <= 32  |  18.2  13.7   4.9   0.5   0.0   0.0   0.0   0.0   0.2   0.7   5.5  17.2 |   60.9
                    |                                                                         |
    Min Temp <= 32  |  30.7  28.2  27.8  20.9   8.1   1.3   0.0   0.0   2.5  14.5  26.5  30.8 |  191.4
    Min Temp <= 20  |  22.6  19.4  10.0   3.2   0.0   0.0   0.0   0.0   0.3   1.2  11.6  22.8 |   91.0
    Min Temp  <= 0  |   3.3   2.3   0.4   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.1   2.7 |    8.8
                    |                                                                         |
Avg Dew Point Temp  |  13.1  13.8  19.1  20.6  27.2  30.6  35.4  35.6  30.5  24.2  19.3  14.0 |   23.6
Avg Wet Bulb Temp   |  18.3  19.8  27.2  33.0  40.4  46.3  52.3  50.7  43.9  35.2  26.9  19.5 |   34.4
                    |                                                                         |
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                    |                                                                         |
Avg Sea Level Pres  | 30.23 30.16 30.08 30.02 29.96 29.95 29.95 29.97 30.01 30.06 30.18 30.19 |  30.06
(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   0.0   0.4   1.2   3.4   5.8   5.6   6.7   3.6   0.3   0.0   0.0 |   27.0
    Heavy Fog       |   2.2   1.9   2.2   1.9   1.2   0.2   0.0   0.0   0.3   1.7   1.9   1.2 |   14.9
    Fog             |   6.6   6.5   5.9   4.9   3.3   2.2   0.7   1.6   2.8   4.4   5.9   6.2 |   50.9
    Hail            |   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.1   0.0   0.0   0.0   0.0 |    0.1
                    |                                                                         |
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                    |                                                                         |
PRECIPITATION (In)  |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Average Monthly     |  0.36  0.48  0.44  0.83  0.98  0.80  0.33  0.70  0.98  0.92  0.30  0.36 |   7.49
                    |                                                                         |
Maximum Daily       |  0.50  0.59  0.46  0.83  0.86  0.70  0.30  1.17  0.91  0.85  0.44  0.50 |   1.17
                    |                                                                         |
    Date of Ext-Day |    29    07    31    24    26    23    29    02    01    25    09    09 |
               -Year|  2005  2001  1999  1999  1999  2003  1996  2007  2008  2006  2004  1997 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
    >= 0.01         |   6.3   6.1   6.2   7.6   7.8   6.4   4.1   6.7   7.2   7.0   4.1   5.7 |   75.1
    >= 0.10         |   1.1   1.5   1.4   2.6   2.9   2.5   1.3   2.4   3.1   2.5   1.1   1.2 |   23.5
    >= 0.25         |   0.2   0.4   0.3   0.7   1.3   1.2   0.3   0.4   1.3   1.2   0.2   0.2 |    7.7
    >= 0.50         |   0.1   0.2   0.0   0.3   0.4   0.4   0.0   0.2   0.3   0.5   0.0   0.1 |    2.6
    >= 1.00         |   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.1   0.0   0.0   0.0   0.0 |    0.1
                    |                                                                         |
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                    |                                                                         |
WIND (MPH)          |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Daily Avg Wind Speed|  12.4  12.1  13.4  12.8  11.8  11.0   9.3   9.3   9.8  11.5  11.1  12.4 |   11.4
Daily Avg Max 2-Min |  25.1  24.7  27.6  29.0  28.8  29.2  27.6  26.6  25.1  25.3  23.3  25.3 |   26.5
Daily Avg Peak Gust |  29.0  28.7  32.6  35.1  35.4  36.4  34.4  33.0  31.2  30.5  27.7  29.8 |   32.0
                    |                                                                         |
Maximum Daily Avg   |  33.5  30.7  29.5  34.1  35.1  25.7  17.9  18.6  21.7  34.1  32.4  30.1 |   35.1
                    |                                                                         |
Maximum 2-Minute Avg|    54    53    53    52    58    54    51    46    52    52    52    49 |     58
                    |                                                                         |
Date of Max 2min-Day|    07    14    28    02    03    02    27    18    22    29    13    13 |
               -Year|  2007  2008  2002  2004  2001  2002  2001  2001  2007  2003  2008  2006 |
                    |                                                                         |
Maximum Peak Gust   |    62    67    60    62    66    62    64    64    60    64    63    59 |     67
                    |                                                                         |
Date of Max Gust-Day|    07    14    28    20    03    02    27    09    22    29    13    30 |
               -Year|  2007  2008  2002  2008  2001  2002  2001  2007  2007  2003  2008  2007 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
   Peak Gust >=30   |  15.6  12.8  19.6  20.3  22.7  24.0  22.7  20.1  16.3  16.4  12.8  16.2 |  219.6
   Peak Gust >=40   |   5.4   5.6   8.3   8.7   9.4  10.1   7.3   6.9   5.4   6.3   4.6   6.5 |   84.5
   Peak Gust >=50   |   1.3   1.3   1.6   2.1   1.5   1.5   1.1   0.9   0.8   0.9   0.6   1.0 |   14.6
                    |                                                                         |
   Max 2-Minute >=30|   9.6   9.7  13.0  14.0  13.8  13.8  11.9  10.9   8.2   9.7   8.2   0.0 |  122.6
   Max 2-Minute >=40|   2.0   2.4   2.7   3.6   2.4   2.0   0.9   1.4   1.3   1.9   1.0   0.0 |   21.5
                    |                                                                         |
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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.