STATION:  BOISE AIR TERMINAL/GOWEN FD AIRPORT (KBOI), ID

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        |  39.4  45.4  55.1  61.7  72.2  81.6  93.4  90.5  79.0  64.8  49.6  39.4 |   64.3
Avg Min Temp        |  26.2  28.2  34.1  38.7  47.1  53.8  62.2  60.6  51.6  41.1  32.5  26.3 |   41.9
Avg Temperature     |  32.8  36.8  44.6  50.2  59.7  67.7  77.8  75.5  65.3  52.9  41.1  32.8 |   53.1
                    |                                                                         |
Extremes:           |                                                                         |
    Extreme Max Temp|    60    61    80    87    99   105   110   105   101    94    78    61 |    110
                    |                                                                         |
    Date of Ext-Day |    01    14    19    27    28    29    13    05    14    01    06    03 |
               -Year|  1997  2000  1997  2000  2003  2008  2002  1998  2000  1997  1999  2007 |
                    |                                                                         |
    Extreme Min Temp|     1    11    17    21    27    37    44    43    31    13    13    -2 |     -2
                    |                                                                         |
    Date of Ext-Day |    05    08    01    05    10    09    11    31    28    31    29    21 |
               -Year|  2004  2001  2002  1997  1999  1999  1997  1999  1999  2002  2006  1998 |
                    |                                                                         |
Heating Degree Days |   999   796   632   445   212    62     3     4    92   383   718   997 |   5345
Cooling Degree Days |     0     0     0     1    46   142   398   331   100     9     0     0 |   1028
                    |                                                                         |
Avg Number of Days: |                                                                         |
    Max Temp >= 90  |   0.0   0.0   0.0   0.0   1.5   7.0  22.9  18.4   4.2   0.2   0.0   0.0 |   54.2
    Max Temp >= 75  |   0.0   0.0   0.2   3.1  12.4  22.5  30.5  30.2  19.9   5.6   0.2   0.0 |  124.5
    Max Temp <= 32  |   5.2   0.9   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   1.0   6.2 |   13.4
                    |                                                                         |
    Min Temp <= 32  |  25.2  21.2  12.2   5.8   1.2   0.0   0.0   0.0   0.1   2.9  14.9  24.8 |  108.3
    Min Temp <= 20  |   6.5   2.9   0.3   0.0   0.0   0.0   0.0   0.0   0.0   0.2   1.6   7.2 |   18.8
    Min Temp  <= 0  |   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.2 |    0.2
                    |                                                                         |
Avg Dew Point Temp  |  25.6  26.1  28.5  32.0  37.3  40.9  44.1  41.3  37.7  31.9  29.9  25.5 |   33.4
Avg Wet Bulb Temp   |  29.9  32.3  37.5  41.9  48.1  53.6  58.8  56.5  50.9  42.4  36.1  29.8 |   43.1
                    |                                                                         |
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                    |                                                                         |
Avg Sea Level Pres  | 30.19 30.15 30.06 29.98 29.94 29.89 29.87 29.89 29.94 30.06 30.15 30.23 |  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   |   0.2   0.0   0.2   0.9   1.8   1.3   2.2   1.4   1.5   0.2   0.0   0.1 |    9.8
    Heavy Fog       |   5.9   2.1   0.9   0.4   0.1   0.2   0.0   0.0   0.0   0.3   2.2   3.3 |   15.4
    Fog             |  18.3  11.2   6.9   5.8   5.4   2.2   1.0   0.5   1.9   4.0  10.4  16.5 |   84.0
    Hail            |   0.2   0.1   0.2   0.2   0.0   0.0   0.2   0.0   0.1   0.0   0.0   0.1 |    1.1
                    |                                                                         |
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                    |                                                                         |
PRECIPITATION (In)  |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Average Monthly     |  1.38  0.92  1.07  1.01  1.44  0.62  0.21  0.12  0.52  0.72  1.13  1.61 |  10.75
                    |                                                                         |
Maximum Daily       |  0.68  0.79  0.61  0.82  0.97  0.88  0.54  0.30  0.78  0.90  0.61  0.75 |   0.97
                    |                                                                         |
    Date of Ext-Day |    27    23    09    23    26    10    19    22    20    12    17    30 |
               -Year|  2003  2000  2000  1997  1998  2007  2004  2003  2008  2000  2001  2005 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
    >= 0.01         |  11.3   9.0   9.1   8.5   7.8   4.2   2.4   1.9   4.3   5.3   9.3  12.3 |   85.5
    >= 0.10         |   5.1   3.9   4.2   3.0   4.2   2.0   0.5   0.4   1.5   2.2   3.9   5.1 |   36.0
    >= 0.25         |   1.3   0.7   1.3   1.2   2.0   0.8   0.2   0.2   0.8   1.3   1.2   1.8 |   12.8
    >= 0.50         |   0.3   0.1   0.3   0.3   0.8   0.2   0.1   0.0   0.2   0.2   0.3   0.6 |    3.3
    >= 1.00         |   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0 |    0.0
                    |                                                                         |
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                    |                                                                         |
WIND (MPH)          |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Daily Avg Wind Speed|   6.8   7.8   8.6   8.5   7.9   8.0   7.2   7.1   7.0   7.0   6.7   7.4 |    7.5
Daily Avg Max 2-Min |  16.2  18.1  19.9  20.4  19.3  19.6  18.5  17.8  17.3  17.0  16.4  17.0 |   18.1
Daily Avg Peak Gust |  19.3  21.8  24.3  25.0  23.7  24.3  22.9  21.7  21.1  20.4  19.6  20.4 |   22.0
                    |                                                                         |
Maximum Daily Avg   |  21.6  20.4  24.9  20.5  18.9  19.7  15.7  17.1  18.0  17.2  19.6  20.4 |   24.9
                    |                                                                         |
Maximum 2-Minute Avg|    39    39    38    46    41    46    44    45    39    38    45    45 |     46
                    |                                                                         |
Date of Max 2min-Day|    04    22    09    23    20    21    26    10    04    29    20    15 |
               -Year|  2008  2003  2006  1998  2008  2008  2003  2006  2007  2003  2008  2000 |
                    |                                                                         |
Maximum Peak Gust   |    49    45    52    52    47    58    51    67    56    46    53    63 |     67
                    |                                                                         |
Date of Max Gust-Day|    04    22    28    23    18    21    26    31    04    29    20    15 |
               -Year|  2008  2003  2007  1998  2002  2008  2003  2004  2007  2003  2008  2000 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
   Peak Gust >=30   |   2.8   4.6   6.7   8.7   6.3   5.7   5.6   3.9   4.1   3.3   3.7   4.6 |   60.0
   Peak Gust >=40   |   0.4   0.6   0.5   1.3   0.6   0.7   0.9   1.2   0.8   0.4   0.3   0.5 |    8.1
   Peak Gust >=50   |   0.0   0.0   0.1   0.2   0.0   0.2   0.1   0.3   0.2   0.0   0.1   0.1 |    1.2
                    |                                                                         |
   Max 2-Minute >=30|   0.8   1.6   1.8   2.4   1.6   2.0   1.9   1.8   1.9   0.8   0.7   0.0 |   17.2
   Max 2-Minute >=40|   0.0   0.0   0.0   0.3   0.1   0.2   0.1   0.2   0.0   0.0   0.1   0.0 |    1.0
                    |                                                                         |
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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.