STATION:  PORTLAND-TROUTDALE AIRPORT (KTTD), OR

CLIMATOLOGICAL SUMMARY.  Period of Record: Jul 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        |  45.8  50.4  55.8  61.0  67.4  73.5  81.4  81.3  75.9  63.2  52.6  45.5 |   62.8
Avg Min Temp        |  36.3  36.9  39.1  41.9  46.9  51.7  56.1  55.4  50.2  45.3  40.9  36.8 |   44.8
Avg Temperature     |  41.0  43.7  47.5  51.4  57.2  62.6  68.7  68.4  63.0  54.2  46.8  41.1 |   53.8
                    |                                                                         |
Extremes:           |                                                                         |
    Extreme Max Temp|    67    66    76    86    96   102   105   106    95    81    71    63 |    106
                    |                                                                         |
    Date of Ext-Day |    18    22    11    26    22    26    21    13    02    01    13    14 |
               -Year|  2005  2002  2005  2004  2001  2006  2006  2002  2003  2001  1999  2002 |
                    |                                                                         |
    Extreme Min Temp|    17    18    26    27    34    41    45    44    37    30    25    16 |     16
                    |                                                                         |
    Date of Ext-Day |    06    20    01    02    10    03    05    28    27    30    12    20 |
               -Year|  2004  2006  2002  2008  1999  1999  1999  2000  1999  2006  2000  1998 |
                    |                                                                         |
Heating Degree Days |   742   602   544   408   256   114    17    16    97   335   546   740 |   4419
Cooling Degree Days |     0     0     0     1    14    42   132   122    38     2     0     0 |    350
                    |                                                                         |
Avg Number of Days: |                                                                         |
    Max Temp >= 90  |   0.0   0.0   0.0   0.0   0.5   2.5   4.8   4.7   1.5   0.0   0.0   0.0 |   14.0
    Max Temp >= 75  |   0.0   0.0   0.1   2.2   6.4  11.6  24.1  24.7  16.0   2.0   0.0   0.0 |   87.2
    Max Temp <= 32  |   1.2   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.1   1.3 |    2.6
                    |                                                                         |
    Min Temp <= 32  |   6.7   5.5   3.3   1.4   0.0   0.0   0.0   0.0   0.0   0.6   3.0   6.0 |   26.5
    Min Temp <= 20  |   0.4   0.1   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.7 |    1.2
    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  |  35.1  35.1  39.0  41.1  46.1  50.2  54.1  54.3  50.0  45.4  40.1  34.9 |   43.8
Avg Wet Bulb Temp   |  38.5  40.0  43.4  46.3  51.4  55.6  59.9  59.9  55.7  49.5  43.7  38.5 |   48.5
                    |                                                                         |
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                    |                                                                         |
Avg Sea Level Pres  | 30.13 30.13 30.10 30.05 30.06 30.04 30.02 30.01 30.01 30.09 30.13 30.17 |  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   |   1.2   0.1   1.3   1.2   0.6   0.6   0.4   0.5   0.6   0.5   0.5   1.2 |    8.7
    Heavy Fog       |   3.5   2.8   1.9   0.9   0.2   0.2   0.1   0.2   0.6   2.7   3.0   1.0 |   17.2
    Fog             |  21.0  16.4  17.9  13.3  11.5   9.2   6.5   6.5   8.7  16.8  17.9  17.1 |  162.5
    Hail            |   0.2   0.2   0.4   0.0   0.1   0.0   0.0   0.0   0.0   0.3   0.1   0.1 |    1.4
                    |                                                                         |
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                    |                                                                         |
PRECIPITATION (In)  |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Average Monthly     |  6.03  3.93  4.51  3.17  2.49  1.91  0.42  0.83  1.57  3.11  6.32  6.52 |  40.81
                    |                                                                         |
Maximum Daily       |  2.51  1.24  1.34  0.88  1.01  1.88  0.43  1.61  2.09  1.19  1.80  2.19 |   2.51
                    |                                                                         |
    Date of Ext-Day |    31    27    07    30    31    24    08    29    30    31    19    13 |
               -Year|  2003  1999  2003  2001  2005  1999  2005  2005  2005  2005  2003  2003 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
    >= 0.01         |  20.4  16.2  19.1  17.1  14.2   9.8   4.2   4.4   5.9  15.3  18.8  19.1 |  164.5
    >= 0.10         |  15.3  10.0  12.6   9.8   8.1   5.2   1.8   1.9   3.3   8.7  13.4  14.6 |  104.7
    >= 0.25         |   8.5   5.9   6.6   5.0   3.2   2.4   0.4   1.3   1.7   4.8   8.7   9.5 |   57.9
    >= 0.50         |   3.9   2.4   2.2   1.4   0.7   0.9   0.0   0.5   1.0   1.5   4.7   4.4 |   23.7
    >= 1.00         |   0.5   0.4   0.5   0.0   0.1   0.2   0.0   0.1   0.3   0.1   1.2   0.8 |    4.2
                    |                                                                         |
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                    |                                                                         |
WIND (MPH)          |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Daily Avg Wind Speed|  12.4  10.7   7.2   5.9   4.8   4.6   4.3   4.0   4.3   5.7   9.7  12.7 |    7.2
Daily Avg Max 2-Min |  23.3  21.5  17.8  15.8  13.9  13.0  11.9  11.9  12.8  15.5  20.8  24.1 |   16.9
Daily Avg Peak Gust |  28.9  26.7  22.1  20.2  18.2  17.2  16.0  16.0  17.2  20.2  26.1  30.0 |   21.6
                    |                                                                         |
Maximum Daily Avg   |  30.7  26.8  23.8  21.3  15.8  12.6   9.4  11.5  20.1  24.2  32.2  31.1 |   32.2
                    |                                                                         |
Maximum 2-Minute Avg|    41    38    36    35    35    30    24    25    30    59    41    51 |     59
                    |                                                                         |
Date of Max 2min-Day|    06    07    08    28    02    09    15    03    22    23    30    20 |
               -Year|  2004  2007  2006  2001  2007  2008  2007  2008  2000  2006  2002  2008 |
                    |                                                                         |
Maximum Peak Gust   |    51    49    44    43    45    39    31    35    87    87    49    67 |     87
                    |                                                                         |
Date of Max Gust-Day|    16    06    03    28    02    09    15    25    23    22    30    20 |
               -Year|  2000  1999  1999  2000  2007  2002  2007  2004  2003  2003  2002  2008 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
   Peak Gust >=30   |  16.3  12.3   6.7   3.3   1.6   0.9   0.2   0.3   2.4   5.4  12.3  17.9 |   79.6
   Peak Gust >=40   |   4.9   1.2   0.5   0.3   0.1   0.0   0.0   0.0   0.1   0.6   2.6   4.4 |   14.6
   Peak Gust >=50   |   0.1   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.1   0.3   0.0   0.2 |    0.7
                    |                                                                         |
   Max 2-Minute >=30|   8.6   4.3   1.2   0.4   0.2   0.1   0.0   0.0   0.2   1.1   4.3   0.0 |   20.5
   Max 2-Minute >=40|   0.1   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.1   0.1   0.0 |    0.3
                    |                                                                         |
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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.