STATION:  MISSOULA INTERNATIONAL AIRPORT (KMSO), 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        |  32.5  37.9  48.3  56.6  66.3  73.2  87.2  84.8  72.3  56.9  41.1  31.8 |   57.4
Avg Min Temp        |  18.6  21.8  27.5  31.7  39.5  46.4  52.3  50.0  42.0  32.5  25.1  19.0 |   33.9
Avg Temperature     |  25.5  29.9  37.9  44.2  52.9  59.8  69.7  67.4  57.2  44.7  33.1  25.4 |   45.6
                    |                                                                         |
Extremes:           |                                                                         |
    Extreme Max Temp|    51    60    78    80    91    98   107   100    96    92    73    53 |    107
                    |                                                                         |
    Date of Ext-Day |    01    28    30    22    19    28    06    11    02    28    12    11 |
               -Year|  1998  2006  2004  1998  2002  2007  2007  1996  1998  2003  1999  2004 |
                    |                                                                         |
    Extreme Min Temp|   -23    -8    -3    17    21    30    36    37    20     1     0   -24 |    -24
                    |                                                                         |
    Date of Ext-Day |    06    17    08    02    08    10    04    31    23    31    06    21 |
               -Year|  2004  2006  2002  1999  1999  1999  2000  1999  2000  2002  2003  1998 |
                    |                                                                         |
Heating Degree Days |  1223   993   840   625   381   186    27    40   250   631   957  1228 |   7380
Cooling Degree Days |     0     0     0     0     5    30   174   114    15     0     0     0 |    338
                    |                                                                         |
Avg Number of Days: |                                                                         |
    Max Temp >= 90  |   0.0   0.0   0.0   0.0   0.2   1.8  13.0  10.3   1.2   0.1   0.0   0.0 |   26.6
    Max Temp >= 75  |   0.0   0.0   0.1   1.2   7.7  13.7  28.6  27.3  13.4   1.4   0.0   0.0 |   93.3
    Max Temp <= 32  |  13.7   5.3   1.3   0.0   0.0   0.0   0.0   0.0   0.0   0.5   6.2  15.6 |   42.6
                    |                                                                         |
    Min Temp <= 32  |  29.7  27.1  25.2  16.1   5.7   0.3   0.0   0.0   1.9  14.8  25.3  29.5 |  175.5
    Min Temp <= 20  |  15.1  10.4   3.2   1.1   0.0   0.0   0.0   0.0   0.1   1.3   8.1  15.4 |   54.7
    Min Temp  <= 0  |   2.2   0.7   0.1   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.2   2.0 |    5.1
                    |                                                                         |
Avg Dew Point Temp  |  20.3  22.3  26.0  29.7  36.9  43.6  45.1  43.1  39.6  32.4  26.3  20.3 |   32.1
Avg Wet Bulb Temp   |  23.9  26.9  32.7  37.8  45.1  51.1  56.1  54.1  47.8  38.6  30.5  23.8 |   39.0
                    |                                                                         |
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                    |                                                                         |
Avg Sea Level Pres  | 30.18 30.16 30.08 30.04 30.00 29.97 29.97 29.98 30.02 30.12 30.17 30.22 |  30.08
(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   |   0.4   0.8   0.4   0.8   2.4   4.5   4.3   4.5   2.0   0.2   0.6   0.4 |   21.3
    Heavy Fog       |   8.5   4.6   2.2   0.8   0.6   0.3   0.1   0.2   0.8   2.5   5.1   6.8 |   32.6
    Fog             |  22.0  15.8  11.0   7.4   7.2   7.0   2.2   2.2   5.6   9.0  17.4  18.8 |  125.6
    Hail            |   0.0   0.0   0.1   0.1   0.3   0.2   0.2   0.3   0.2   0.0   0.0   0.0 |    1.3
                    |                                                                         |
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                    |                                                                         |
PRECIPITATION (In)  |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Average Monthly     |  0.88  0.75  0.86  1.23  1.91  2.22  0.77  0.84  1.14  1.01  1.12  1.11 |  13.83
                    |                                                                         |
Maximum Daily       |  0.45  0.38  0.44  1.75  0.99  1.49  1.00  0.85  1.01  0.90  0.80  0.82 |   1.75
                    |                                                                         |
    Date of Ext-Day |    31    23    11    06    26    03    05    26    23    01    12    29 |
               -Year|  2003  1999  1997  2006  1998  2001  1998  2004  2007  2000  2008  1996 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
    >= 0.01         |  12.8   9.8  11.2  11.8  11.8  12.0   5.3   6.6   8.4   8.2  10.6  13.5 |  122.0
    >= 0.10         |   3.4   2.3   3.2   3.6   5.8   6.3   2.5   2.2   3.2   3.0   3.4   3.5 |   42.3
    >= 0.25         |   0.6   0.8   0.7   1.3   3.0   2.8   0.9   1.1   1.4   1.2   1.4   1.2 |   16.3
    >= 0.50         |   0.0   0.0   0.0   0.2   0.9   1.2   0.3   0.5   0.5   0.4   0.5   0.2 |    4.7
    >= 1.00         |   0.0   0.0   0.0   0.1   0.0   0.1   0.1   0.0   0.1   0.0   0.0   0.0 |    0.3
                    |                                                                         |
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                    |                                                                         |
WIND (MPH)          |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Daily Avg Wind Speed|   3.4   3.8   5.3   6.0   5.9   5.9   5.5   5.0   4.3   4.0   3.5   3.9 |    4.7
Daily Avg Max 2-Min |  12.8  13.3  18.1  19.6  19.7  19.4  19.7  18.9  16.7  15.0  13.1  13.3 |   16.6
Daily Avg Peak Gust |  15.1  15.7  21.9  23.9  24.1  23.9  24.7  23.6  20.3  18.1  15.6  15.7 |   20.2
                    |                                                                         |
Maximum Daily Avg   |  20.5  20.3  17.5  17.6  14.3  15.8  14.1  12.7  16.5  15.4  16.7  19.7 |   20.5
                    |                                                                         |
Maximum 2-Minute Avg|    47    41    43    41    38    43    52    46    48    37    33    44 |     52
                    |                                                                         |
Date of Max 2min-Day|    30    16    29    04    25    04    10    05    16    28    18    15 |
               -Year|  2004  2007  1999  2000  2003  2007  1998  2003  2000  2003  2003  2006 |
                    |                                                                         |
Maximum Peak Gust   |    60    49    52    49    49    55    61    58    55    52    43    53 |     61
                    |                                                                         |
Date of Max Gust-Day|    30    16    13    04    22    04    10    05    01    28    07    15 |
               -Year|  2004  2007  2001  2000  2006  2007  1998  2007  2004  2003  1996  2006 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
   Peak Gust >=30   |   2.7   1.7   6.2   5.9   6.3   6.4   7.2   7.2   4.3   2.8   2.5   2.7 |   55.7
   Peak Gust >=40   |   0.4   0.3   1.3   1.0   1.3   1.1   1.3   1.3   0.6   0.4   0.5   0.5 |   10.1
   Peak Gust >=50   |   0.1   0.0   0.2   0.0   0.0   0.2   0.3   0.2   0.2   0.1   0.0   0.1 |    1.3
                    |                                                                         |
   Max 2-Minute >=30|   0.8   0.6   2.2   1.9   1.9   1.6   2.1   1.8   1.2   0.8   1.2   0.0 |   16.0
   Max 2-Minute >=40|   0.2   0.1   0.2   0.1   0.0   0.1   0.4   0.2   0.2   0.0   0.0   0.0 |    1.4
                    |                                                                         |
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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.