STATION:  SHELTON SANDERSON FIELD AIRPORT (KSHN), WA

CLIMATOLOGICAL SUMMARY.  Period of Record: May 1998 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        |  45.4  48.8  52.4  57.9  64.2  69.6  76.3  76.4  71.8  60.2  50.8  44.3 |   59.9
Avg Min Temp        |  33.2  32.0  34.8  37.1  42.9  48.2  51.9  51.7  45.9  40.8  36.1  33.3 |   40.7
Avg Temperature     |  39.3  40.4  43.6  47.5  53.5  58.9  64.1  64.1  58.9  50.5  43.5  38.8 |   50.3
                    |                                                                         |
Extremes:           |                                                                         |
    Extreme Max Temp|    61    63    78    82    91    95   102    96    94    79    77    59 |    102
                    |                                                                         |
    Date of Ext-Day |    19    02    29    11    27    26    21    31    03    08    17    24 |
               -Year|  2005  2005  2004  2004  2005  2006  2006  1998  2003  2000  2000  2005 |
                    |                                                                         |
    Extreme Min Temp|     8    14    22    24    28    35    39    39    30    17    17     6 |      6
                    |                                                                         |
    Date of Ext-Day |    04    19    02    03    07    08    05    24    28    31    29    22 |
               -Year|  2004  2006  2002  2007  2002  2002  2002  2003  1999  2002  2006  1998 |
                    |                                                                         |
Heating Degree Days |   797   695   662   526   357   197    74    67   190   448   646   812 |   5472
Cooling Degree Days |     0     0     0     0     2    13    46    38     7     0     0     0 |    106
                    |                                                                         |
Avg Number of Days: |                                                                         |
    Max Temp >= 90  |   0.0   0.0   0.0   0.0   0.1   0.9   1.9   2.0   0.7   0.0   0.0   0.0 |    5.6
    Max Temp >= 75  |   0.0   0.0   0.1   1.3   3.6   7.5  16.3  16.7  10.5   0.9   0.2   0.0 |   57.1
    Max Temp <= 32  |   0.5   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.1   0.8 |    1.4
                    |                                                                         |
    Min Temp <= 32  |  13.7  14.5  12.0   7.3   1.7   0.0   0.0   0.0   0.4   4.5  10.4  13.6 |   78.0
    Min Temp <= 20  |   1.4   0.4   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.2   0.7   0.8 |    3.6
    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   0.0 |    0.0
                    |                                                                         |
Avg Dew Point Temp  |  36.5  35.1  37.7  39.4  44.2  48.7  52.3  52.9  49.2  44.8  39.9  35.9 |   43.1
Avg Wet Bulb Temp   |  38.1  38.0  40.9  43.6  48.7  53.1  56.8  57.1  53.3  47.4  41.9  37.6 |   46.4
                    |                                                                         |
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                    |                                                                         |
Avg Sea Level Pres  | 30.11 30.12 30.09 30.05 30.06 30.03 30.04 30.02 30.02 30.09 30.13 30.14 |  30.07
(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   |   0.1   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.2 |    0.3
    Heavy Fog       |   9.5   6.1   3.6   3.9   1.8   0.9   1.5   3.1   4.5   6.9   9.2   9.6 |   60.6
    Fog             |  25.4  20.0  21.9  17.5  14.7  12.1  10.8  13.7  15.8  21.1  22.7  23.4 |  219.3
    Hail            |   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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                    |                                                                         |
PRECIPITATION (In)  |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Average Monthly     | 11.86  6.30  6.45  3.54  2.31  1.61  0.62  1.22  1.56  4.83 11.79 11.16 |  63.25
                    |                                                                         |
Maximum Daily       |  4.23  2.40  2.69  1.15  1.49  0.95  0.86  1.60  1.77  3.37  4.52  3.60 |   4.52
                    |                                                                         |
    Date of Ext-Day |    17    24    26    13    14    24    21    22    29    17    06    27 |
               -Year|  2005  1999  2005  2002  2001  2001  2007  2001  2005  2003  2006  1998 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
    >= 0.01         |  22.3  16.9  19.5  16.2  13.2   8.3   4.0   6.7   8.5  16.3  19.6  21.9 |  173.4
    >= 0.10         |  16.9  11.6  13.6   9.6   6.5   4.0   1.5   2.6   3.9  10.0  14.0  15.5 |  109.7
    >= 0.25         |  12.7   7.2   8.5   5.2   2.6   2.6   1.1   1.3   2.1   6.6  10.9  12.5 |   73.3
    >= 0.50         |   7.9   4.3   4.4   1.9   1.0   0.9   0.3   0.6   0.6   3.1   7.2   7.2 |   39.5
    >= 1.00         |   3.1   1.6   1.1   0.1   0.3   0.0   0.0   0.3   0.2   0.7   3.9   3.5 |   14.8
                    |                                                                         |
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                    |                                                                         |
WIND (MPH)          |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Daily Avg Wind Speed|   4.4   4.7   5.9   6.3   7.5   7.8   7.6   7.0   5.2   4.8   4.3   4.6 |    5.8
Daily Avg Max 2-Min |  14.1  14.9  17.5  17.3  18.2  17.8  16.9  16.5  14.5  14.4  14.1  14.6 |   15.9
Daily Avg Peak Gust |  18.1  19.3  22.5  22.0  22.9  22.3  21.2  20.7  18.3  18.4  18.2  19.0 |   20.2
                    |                                                                         |
Maximum Daily Avg   |  16.0  18.9  16.3  17.5  91.5  16.6  15.8  15.0  17.8  18.2  19.0  18.4 |   91.5
                    |                                                                         |
Maximum 2-Minute Avg|    39    39    39    43    33    34    32    35    29    38    36    40 |     43
                    |                                                                         |
Date of Max 2min-Day|    05    22    03    13    08    15    13    17    24    18    24    14 |
               -Year|  2007  1999  1999  2002  2007  1998  1999  2008  1999  2007  1998  2006 |
                    |                                                                         |
Maximum Peak Gust   |    54    54    52    61    41    46    37    44    39    51    47    55 |     61
                    |                                                                         |
Date of Max Gust-Day|    05    22    03    13    08    15    13    17    24    18    24    13 |
               -Year|  2007  1999  1999  2002  2007  1998  1999  2008  1999  2007  1998  2006 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
   Peak Gust >=30   |   4.7   4.6   6.2   4.9   5.8   3.9   2.3   2.2   2.0   3.1   4.4   5.7 |   50.0
   Peak Gust >=40   |   0.8   1.1   1.0   0.7   0.2   0.1   0.0   0.1   0.0   0.3   1.4   1.6 |    7.3
   Peak Gust >=50   |   0.1   0.3   0.2   0.2   0.0   0.0   0.0   0.0   0.0   0.1   0.0   0.3 |    1.2
                    |                                                                         |
   Max 2-Minute >=30|   0.8   1.3   1.1   0.7   0.4   0.2   0.4   0.2   0.0   0.4   1.1   0.0 |    6.6
   Max 2-Minute >=40|   0.0   0.0   0.0   0.1   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0 |    0.1
                    |                                                                         |
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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.