STATION:  TACOMA NARROWS AIRPORT (KTIW), WA

CLIMATOLOGICAL SUMMARY.  Period of Record: Jan 1999 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        |  46.3  48.9  52.2  57.4  63.4  69.2  74.9  74.7  68.6  58.8  50.3  45.6 |   59.2
Avg Min Temp        |  37.4  37.1  39.3  41.9  46.8  51.3  54.7  55.0  51.2  46.6  40.8  37.5 |   45.0
Avg Temperature     |  41.8  43.0  45.7  49.7  55.1  60.3  64.8  64.8  59.9  52.7  45.5  41.5 |   52.1
                    |                                                                         |
Extremes:           |                                                                         |
    Extreme Max Temp|    62    68    76    80    88    94    97    91    88    92    64    61 |     97
                    |                                                                         |
    Date of Ext-Day |    19    26    29    16    27    13    24    09    04    16    15    14 |
               -Year|  2005  2008  2004  1999  2005  2002  2004  2004  2003  2000  2001  2002 |
                    |                                                                         |
    Extreme Min Temp|    19    26    30    33    36    43    47    48    41    33    20    20 |     19
                    |                                                                         |
    Date of Ext-Day |    12    17    07    01    06    08    02    28    23    31    29    20 |
               -Year|  2007  2006  1999  1999  2002  2002  1999  2000  2000  2003  2006  2008 |
                    |                                                                         |
Heating Degree Days |   718   622   597   460   311   166    58    46   161   382   584   727 |   4832
Cooling Degree Days |     0     0     0     0     4    24    52    41     8     1     0     0 |    130
                    |                                                                         |
Avg Number of Days: |                                                                         |
    Max Temp >= 90  |   0.0   0.0   0.0   0.0   0.0   0.3   0.9   0.2   0.0   0.1   0.0   0.0 |    1.5
    Max Temp >= 75  |   0.0   0.0   0.1   0.6   2.6   7.2  15.7  15.3   5.3   0.1   0.0   0.0 |   46.9
    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   0.5 |    1.1
                    |                                                                         |
    Min Temp <= 32  |   5.2   4.4   1.5   0.0   0.0   0.0   0.0   0.0   0.0   0.0   2.6   4.1 |   17.8
    Min Temp <= 20  |   0.1   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.1   0.1 |    0.3
    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  |  37.6  36.7  38.4  39.8  44.0  48.0  51.7  52.6  49.6  45.7  40.9  37.5 |   43.5
Avg Wet Bulb Temp   |  39.9  40.2  42.2  44.7  49.2  53.3  56.7  57.5  53.9  49.0  43.4  39.8 |   47.5
                    |                                                                         |
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                    |                                                                         |
Avg Sea Level Pres  | 30.10 30.12 30.09 30.05 30.07 30.04 30.05 30.02 30.04 30.11 30.12 30.13 |  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   |   2.7   2.4   1.4   1.8   1.2   1.2   0.2   1.4   0.9   2.8   0.3   1.7 |   18.0
    Heavy Fog       |   7.1   5.3   2.3   1.1   0.6   0.6   0.6   1.8   3.1   6.0   6.0   6.4 |   40.9
    Fog             |  22.7  18.0  16.5  11.8   9.4   8.2   5.0   8.0  11.5  18.1  19.2  20.1 |  168.5
    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     |  7.16  3.64  4.11  2.48  1.84  1.49  0.54  1.02  1.09  3.50  6.92  5.98 |  39.76
                    |                                                                         |
Maximum Daily       |  2.30  1.43  1.75  1.20  0.83  1.33  0.87  1.64  0.78  5.52  3.33  2.21 |   5.52
                    |                                                                         |
    Date of Ext-Day |    17    01    26    13    27    27    16    22    30    20    06    03 |
               -Year|  2005  2000  2005  2002  2004  2001  1999  2001  2007  2003  2006  2007 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
    >= 0.01         |  24.1  17.0  20.0  14.8  12.6   9.2   3.9   6.3   9.7  17.4  20.7  21.3 |  177.1
    >= 0.10         |  15.0   9.2  10.8   7.7   5.7   3.5   1.8   2.3   3.4   7.2  12.0  13.3 |   91.9
    >= 0.25         |   9.0   5.3   6.2   3.5   2.4   1.6   0.8   1.3   1.2   4.4   8.1   8.3 |   52.2
    >= 0.50         |   4.8   2.2   2.4   1.1   0.7   0.6   0.1   0.6   0.4   1.6   4.0   3.2 |   21.7
    >= 1.00         |   1.5   0.3   0.5   0.1   0.0   0.2   0.0   0.1   0.0   0.3   2.0   1.1 |    6.2
                    |                                                                         |
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                    |                                                                         |
WIND (MPH)          |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Daily Avg Wind Speed|   6.9   6.6   7.3   6.5   6.4   6.3   5.8   5.3   5.2   6.0   6.3   6.6 |    6.3
Daily Avg Max 2-Min |  16.2  15.7  16.4  14.9  14.1  13.7  12.6  12.3  13.0  14.3  15.5  16.3 |   14.6
Daily Avg Peak Gust |  21.1  20.6  21.4  19.5  18.6  18.0  16.5  16.0  16.7  18.4  20.4  21.6 |   19.1
                    |                                                                         |
Maximum Daily Avg   |  19.0  20.3  20.6  15.6  13.5  13.8  11.7  12.5  15.1  18.4  21.4  20.2 |   21.4
                    |                                                                         |
Maximum 2-Minute Avg|    37    38    37    32    24    23    22    24    36    32    33    40 |     40
                    |                                                                         |
Date of Max 2min-Day|    16    07    03    29    02    05    28    04    24    22    18    14 |
               -Year|  2000  2008  1999  2001  2002  1999  2001  2002  1999  2001  2003  2006 |
                    |                                                                         |
Maximum Peak Gust   |    47    51    54    38    35    35    29    31    45    45    47    56 |     56
                    |                                                                         |
Date of Max Gust-Day|    16    04    03    29    02    09    28    04    24    17    12    14 |
               -Year|  2000  2006  1999  2001  2002  2008  2001  2002  1999  2003  2007  2006 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
   Peak Gust >=30   |   5.7   4.4   4.3   1.7   1.1   0.7   0.0   0.1   0.5   2.8   5.2   7.7 |   34.3
   Peak Gust >=40   |   0.8   0.7   0.5   0.0   0.0   0.0   0.0   0.0   0.1   0.3   0.9   1.8 |    5.2
   Peak Gust >=50   |   0.0   0.2   0.1   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.2 |    0.5
                    |                                                                         |
   Max 2-Minute >=30|   1.3   1.2   0.7   0.1   0.0   0.0   0.0   0.0   0.1   0.6   0.8   0.0 |    4.8
   Max 2-Minute >=40|   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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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.