STATION:  BILLINGS LOGAN INTERNATIONAL AIRPORT (KBIL), MT

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        |  36.1  40.8  48.7  56.9  67.4  76.0  89.1  86.4  73.7  59.2  46.0  36.2 |   59.7
Avg Min Temp        |  18.0  21.6  26.2  34.3  43.2  51.8  60.2  57.7  48.2  37.4  27.0  19.1 |   37.1
Avg Temperature     |  27.0  31.2  37.4  45.6  55.3  63.9  74.6  72.0  60.9  48.3  36.5  27.7 |   48.4
                    |                                                                         |
Extremes:           |                                                                         |
    Extreme Max Temp|    62    69    80    83    94   101   108   103    99    87    77    67 |    108
                    |                                                                         |
    Date of Ext-Day |    24    27    31    28    29    27    14    03    02    01    07    11 |
               -Year|  2005  2006  2004  2007  2003  2002  2002  2001  1998  1997  1999  2004 |
                    |                                                                         |
    Extreme Min Temp|   -30   -17    -9     3    24    34    42    39    25     6   -11   -20 |    -30
                    |                                                                         |
    Date of Ext-Day |    12    24    08    02    13    11    16    17    22    31    28    26 |
               -Year|  1997  2003  2003  2002  2004  2008  1999  2002  2000  1996  2006  1996 |
                    |                                                                         |
Heating Degree Days |  1177   955   855   583   315   104     7    14   178   522   856  1158 |   6724
Cooling Degree Days |     0     0     0     0    15    71   306   232    55     4     0     0 |    683
                    |                                                                         |
Avg Number of Days: |                                                                         |
    Max Temp >= 90  |   0.0   0.0   0.0   0.0   0.4   2.3  15.4  12.6   2.4   0.0   0.0   0.0 |   33.0
    Max Temp >= 75  |   0.0   0.0   0.4   2.5   9.3  17.2  29.5  28.2  15.3   3.5   0.2   0.0 |  106.1
    Max Temp <= 32  |   9.5   6.2   3.9   1.3   0.0   0.0   0.0   0.0   0.1   0.9   5.3  10.0 |   37.2
                    |                                                                         |
    Min Temp <= 32  |  27.6  25.6  22.9  11.0   2.2   0.0   0.0   0.0   0.5   7.5  19.6  27.4 |  144.3
    Min Temp <= 20  |  15.4  11.3   7.5   1.4   0.0   0.0   0.0   0.0   0.0   1.0   6.7  14.8 |   58.1
    Min Temp  <= 0  |   4.3   1.6   1.2   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.6   3.2 |   10.9
                    |                                                                         |
Avg Dew Point Temp  |  14.6  16.9  21.3  28.4  36.7  44.9  47.5  44.7  38.9  31.2  21.3  15.3 |   30.1
Avg Wet Bulb Temp   |  22.5  25.6  30.7  37.9  46.1  53.4  58.8  56.5  49.3  40.3  30.5  23.4 |   39.6
                    |                                                                         |
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                    |                                                                         |
Avg Sea Level Pres  | 30.11 30.09 30.07 30.04 29.99 29.93 29.91 29.94 29.98 30.07 30.11 30.12 |  30.03
(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   0.3   2.1   4.5   8.3   9.1   6.2   1.8   0.2   0.1   0.0 |   32.6
    Heavy Fog       |   1.7   2.4   2.4   2.3   1.2   0.6   0.1   0.2   0.9   1.3   2.0   1.6 |   16.7
    Fog             |   8.8   9.4  10.3   9.0   7.4   5.9   2.1   1.8   4.3   7.5   6.5   7.8 |   80.9
    Hail            |   0.3   0.2   0.3   0.3   0.4   0.8   0.7   0.0   0.2   0.1   0.2   0.1 |    3.4
                    |                                                                         |
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                    |                                                                         |
PRECIPITATION (In)  |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Average Monthly     |  0.44  0.42  0.85  1.68  1.83  2.07  1.15  0.59  1.42  1.32  0.51  0.42 |  12.70
                    |                                                                         |
Maximum Daily       |  0.57  0.65  1.13  1.04  1.62  2.91  1.61  1.20  1.03  1.11  0.61  0.43 |   2.91
                    |                                                                         |
    Date of Ext-Day |    03    25    29    19    22    08    20    02    16    04    09    26 |
               -Year|  1997  2000  2006  2007  2007  1997  1997  1998  2006  2005  2006  2003 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
    >= 0.01         |   6.0   5.7   7.9  10.0  10.3  11.4   7.2   5.2   7.5   8.0   5.8   5.5 |   90.5
    >= 0.10         |   1.5   1.4   2.3   4.8   5.2   5.1   2.3   1.3   3.9   3.6   1.7   1.3 |   34.4
    >= 0.25         |   0.3   0.3   1.0   2.0   2.2   2.3   1.2   0.6   1.9   2.1   0.4   0.4 |   14.7
    >= 0.50         |   0.1   0.1   0.4   0.8   0.8   0.8   0.5   0.3   0.9   0.5   0.2   0.0 |    5.3
    >= 1.00         |   0.0   0.0   0.1   0.1   0.2   0.3   0.2   0.1   0.1   0.1   0.0   0.0 |    1.1
                    |                                                                         |
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                    |                                                                         |
WIND (MPH)          |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Daily Avg Wind Speed|  13.1  12.2  10.8  10.2  10.1   9.6   8.9   8.8   9.3  10.3  11.9  13.0 |   10.7
Daily Avg Max 2-Min |  24.4  23.4  23.1  22.6  23.3  23.6  23.5  22.2  20.5  21.3  23.1  24.6 |   23.0
Daily Avg Peak Gust |  28.9  27.9  27.7  27.5  28.7  29.0  28.9  27.3  25.0  25.8  27.7  29.2 |   27.8
                    |                                                                         |
Maximum Daily Avg   |  28.1  26.7  29.1  24.2  23.7  23.4  17.2  17.0  22.4  25.2  26.0  26.0 |   29.1
                    |                                                                         |
Maximum 2-Minute Avg|    43    48    53    60    45    47    61    59    51    56    46    49 |     61
                    |                                                                         |
Date of Max 2min-Day|    10    02    16    30    20    13    16    16    06    31    27    28 |
               -Year|  2000  1999  1999  2001  2001  1998  2002  2002  1997  1999  2007  1998 |
                    |                                                                         |
Maximum Peak Gust   |    55    61    63    69    62    62    85    70    62    70    58    61 |     85
                    |                                                                         |
Date of Max Gust-Day|    10    02    16    30    21    26    07    16    06    31    13    28 |
               -Year|  2000  1999  1999  2001  2002  2001  2007  2002  1997  1999  2008  1998 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
   Peak Gust >=30   |  15.7  12.2  12.5  10.9  12.6  12.5  12.4  10.6   7.6   9.2  12.7  15.1 |  144.0
   Peak Gust >=40   |   2.6   3.3   3.8   2.8   3.1   3.8   4.9   3.2   1.7   2.0   2.7   3.8 |   37.8
   Peak Gust >=50   |   0.3   0.6   0.4   0.2   0.5   0.6   1.3   0.9   0.3   0.6   0.5   1.0 |    7.3
                    |                                                                         |
   Max 2-Minute >=30|   6.6   6.1   7.2   4.8   6.3   6.9   6.8   5.3   3.1   3.7   6.2   0.0 |   63.0
   Max 2-Minute >=40|   0.6   0.9   0.8   0.4   0.6   1.0   1.7   0.5   0.2   0.7   0.6   0.0 |    8.2
                    |                                                                         |
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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.