STATION:  PORTLAND-HILLSBORO AIRPORT (KHIO), OR

CLIMATOLOGICAL SUMMARY.  Period of Record: Jun 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        |  46.1  50.8  54.8  60.2  67.1  72.9  81.3  81.4  76.0  63.2  52.0  45.8 |   62.6
Avg Min Temp        |  33.5  33.3  36.2  38.5  44.1  48.4  52.1  51.2  45.7  40.8  36.5  33.5 |   41.2
Avg Temperature     |  39.8  42.1  45.5  49.4  55.6  60.6  66.7  66.3  60.9  52.0  44.3  39.6 |   51.9
                    |                                                                         |
Extremes:           |                                                                         |
    Extreme Max Temp|    64    65    77    87    94   102   108   103    97    81    67    60 |    108
                    |                                                                         |
    Date of Ext-Day |    18    27    29    26    22    26    21    15    02    01    13    12 |
               -Year|  2005  2005  2004  2004  2001  2006  2006  2008  2006  2001  1999  1998 |
                    |                                                                         |
    Extreme Min Temp|    18    16    25    25    30    35    39    38    30    20    16     4 |      4
                    |                                                                         |
    Date of Ext-Day |    06    19    01    01    08    04    02    31    27    31    02    22 |
               -Year|  2004  2006  2002  2008  2002  2001  2000  2008  1999  2002  2002  1998 |
                    |                                                                         |
Heating Degree Days |   781   648   603   469   299   161    41    42   147   404   622   786 |   5002
Cooling Degree Days |     0     0     0     0     8    30    93    82    23     1     0     0 |    236
                    |                                                                         |
Avg Number of Days: |                                                                         |
    Max Temp >= 90  |   0.0   0.0   0.0   0.0   0.7   2.0   5.5   5.0   2.0   0.0   0.0   0.0 |   15.2
    Max Temp >= 75  |   0.0   0.0   0.2   2.1   6.2  10.7  23.9  23.8  16.5   3.0   0.0   0.0 |   86.4
    Max Temp <= 32  |   0.4   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   1.1 |    1.5
                    |                                                                         |
    Min Temp <= 32  |  13.5  13.6   8.5   4.4   0.6   0.0   0.0   0.0   0.2   3.5   9.9  13.4 |   67.4
    Min Temp <= 20  |   1.1   0.3   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.2   0.4   0.9 |    2.9
    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  |  36.1  35.6  39.1  41.0  45.8  49.6  52.9  52.6  48.7  43.7  38.9  35.2 |   43.3
Avg Wet Bulb Temp   |  38.2  39.2  42.6  45.4  50.5  54.6  58.7  58.4  53.8  47.0  41.1  37.1 |   47.2
                    |                                                                         |
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                    |                                                                         |
Avg Sea Level Pres  | 30.13 30.12 30.11 30.06 30.07 30.05 30.03 30.01 30.02 30.10 30.13 30.19 |  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   |   0.3   0.4   0.8   1.5   0.5   0.9   0.5   0.8   0.7   0.4   0.2   0.4 |    7.4
    Heavy Fog       |   9.6   4.7   3.2   2.3   0.6   0.4   0.2   0.6   2.5   9.5   8.0   6.5 |   48.0
    Fog             |  24.2  19.4  18.0  13.5  11.8   8.4   5.7   7.8  12.7  22.0  22.7  22.2 |  188.4
    Hail            |   0.1   0.0   0.0   0.1   0.0   0.1   0.0   0.0   0.0   0.0   0.0   0.0 |    0.3
                    |                                                                         |
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                    |                                                                         |
PRECIPITATION (In)  |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Average Monthly     |  6.06  3.39  3.38  2.26  1.72  1.01  0.25  0.64  0.92  2.51  5.79  6.48 |  34.41
                    |                                                                         |
Maximum Daily       |  1.92  1.29  1.20  1.09  0.82  0.77  0.35  0.79  1.28  1.09  2.32  2.19 |   2.32
                    |                                                                         |
    Date of Ext-Day |    31    17    27    12    09    28    03    22    30    31    25    27 |
               -Year|  2003  2003  2005  2003  2005  2002  1999  2004  2005  2005  1998  1998 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
    >= 0.01         |  22.0  16.0  19.1  16.3  12.5   8.5   2.9   3.9   6.2  15.4  20.6  22.1 |  165.5
    >= 0.10         |  13.6   9.7  10.3   7.5   5.8   3.4   0.9   2.0   2.5   6.3  11.5  14.3 |   87.9
    >= 0.25         |   8.9   4.7   4.5   2.8   2.3   1.1   0.3   0.8   1.0   3.4   7.3   9.4 |   46.5
    >= 0.50         |   4.0   1.5   1.2   0.7   0.4   0.2   0.0   0.3   0.4   1.3   4.1   3.7 |   17.8
    >= 1.00         |   0.8   0.5   0.3   0.1   0.0   0.0   0.0   0.0   0.1   0.4   1.0   1.1 |    4.3
                    |                                                                         |
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                    |                                                                         |
WIND (MPH)          |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Daily Avg Wind Speed|   4.7   5.1   5.3   5.2   4.7   5.0   5.1   4.7   4.2   3.8   4.5   5.0 |    4.8
Daily Avg Max 2-Min |  13.9  14.7  15.5  15.5  14.5  14.3  14.5  14.3  13.7  12.7  13.6  14.5 |   14.3
Daily Avg Peak Gust |  17.3  18.4  19.3  19.2  18.1  17.9  18.1  17.6  16.9  16.0  17.0  18.3 |   17.8
                    |                                                                         |
Maximum Daily Avg   |  19.3  21.7  16.7  15.2  11.6  11.4   9.4  11.8  13.7  13.4  16.4  18.6 |   21.7
                    |                                                                         |
Maximum 2-Minute Avg|    37    35    36    28    28    26    25    23    28    30    39    39 |     39
                    |                                                                         |
Date of Max 2min-Day|    16    03    03    23    02    15    20    14    25    28    05    14 |
               -Year|  2000  2006  1999  2008  2007  1998  1999  2006  1999  1999  2008  2006 |
                    |                                                                         |
Maximum Peak Gust   |    52    48    44    40    36    32    30    36    36    39    58    54 |     58
                    |                                                                         |
Date of Max Gust-Day|    04    04    02    23    02    15    30    29    21    28    05    14 |
               -Year|  2008  2006  1999  2008  2007  1998  2007  2008  2000  1999  2008  2006 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
   Peak Gust >=30   |   3.2   3.6   3.1   1.8   0.6   0.4   0.1   0.3   0.7   1.6   2.8   4.6 |   22.9
   Peak Gust >=40   |   0.6   0.6   0.2   0.1   0.0   0.0   0.0   0.0   0.0   0.0   0.4   0.9 |    2.8
   Peak Gust >=50   |   0.1   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.2   0.2 |    0.5
                    |                                                                         |
   Max 2-Minute >=30|   0.5   0.7   0.4   0.0   0.0   0.0   0.0   0.0   0.0   0.1   0.5   0.0 |    2.2
   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.