STATION:  PASCO-TRI-CITIES AIRPORT (KPSC), WA

CLIMATOLOGICAL SUMMARY.  Period of Record: Feb 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        |  42.2  49.8  59.8  66.8  75.7  83.3  93.3  90.7  80.8  65.9  51.0  41.3 |   66.7
Avg Min Temp        |  28.4  28.7  33.4  37.6  45.7  51.9  57.1  55.5  46.0  37.7  32.3  27.6 |   40.2
Avg Temperature     |  35.3  39.2  46.6  52.2  60.7  67.6  75.2  73.1  63.4  51.8  41.7  34.5 |   53.4
                    |                                                                         |
Extremes:           |                                                                         |
    Extreme Max Temp|    67    68    80    94   101   106   113   111   101    88    77    67 |    113
                    |                                                                         |
    Date of Ext-Day |    07    17    30    30    23    27    14    04    01    21    13    03 |
               -Year|  2002  2007  2003  1998  2001  2006  2001  1998  1998  2003  1999  2007 |
                    |                                                                         |
    Extreme Min Temp|   -19     5    16    21    28    37    42    40    26     9    11    -6 |    -19
                    |                                                                         |
    Date of Ext-Day |    04    19    02    01    05    07    05    31    24    31    01    16 |
               -Year|  2004  2006  2002  2008  1999  2002  1999  2008  2000  2002  2002  2008 |
                    |                                                                         |
Heating Degree Days |   920   728   571   384   168    34     3     5    97   411   700   946 |   4969
Cooling Degree Days |     0     0     0     1    35   112   319   257    50     1     0     0 |    775
                    |                                                                         |
Avg Number of Days: |                                                                         |
    Max Temp >= 90  |   0.0   0.0   0.0   0.1   2.6   6.7  22.3  18.1   4.3   0.0   0.0   0.0 |   54.1
    Max Temp >= 75  |   0.0   0.0   0.8   4.8  16.0  25.7  30.7  30.4  23.6   3.8   0.2   0.0 |  136.0
    Max Temp <= 32  |   4.1   0.2   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.6   5.3 |   10.1
                    |                                                                         |
    Min Temp <= 32  |  20.9  19.5  15.3   6.7   1.9   0.0   0.0   0.0   0.5   8.7  16.4  21.9 |  111.9
    Min Temp <= 20  |   4.8   3.8   0.6   0.0   0.0   0.0   0.0   0.0   0.0   0.6   2.7   5.1 |   17.6
    Min Temp  <= 0  |   0.2   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.5 |    0.7
                    |                                                                         |
Avg Dew Point Temp  |  30.2  31.2  34.3  37.8  44.4  48.4  52.2  51.7  46.4  40.1  34.8  29.8 |   40.1
Avg Wet Bulb Temp   |  33.3  35.6  41.1  45.7  52.6  57.3  62.1  60.4  54.0  45.8  38.5  32.7 |   46.6
                    |                                                                         |
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                    |                                                                         |
Avg Sea Level Pres  | 30.18 30.15 30.06 30.01 29.98 29.94 29.91 29.91 29.96 30.08 30.17 30.22 |  30.05
(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   |   0.5   0.5   0.4   0.5   0.8   0.9   1.0   0.6   0.3   0.1   0.2   0.3 |    6.1
    Heavy Fog       |   3.6   1.9   0.4   0.2   0.1   0.0   0.1   0.0   0.3   1.1   5.1   3.7 |   16.4
    Fog             |  18.0  12.2   5.1   4.0   3.7   2.3   1.1   1.5   4.2   9.5  12.5  16.7 |   90.9
    Hail            |   0.0   0.0   0.1   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0 |    0.1
                    |                                                                         |
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                    |                                                                         |
PRECIPITATION (In)  |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Average Monthly     |  1.05  0.64  0.54  0.50  0.64  0.68  0.14  0.17  0.31  0.47  0.87  1.11 |   7.13
                    |                                                                         |
Maximum Daily       |  0.64  0.55  0.38  0.39  0.49  0.59  0.40  0.21  0.72  0.43  0.82  0.73 |   0.82
                    |                                                                         |
    Date of Ext-Day |    27    23    13    03    15    08    07    05    30    01    05    13 |
               -Year|  2008  2002  2008  2005  2005  2004  2002  2004  2005  2000  1998  2003 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
    >= 0.01         |  10.6   7.0   6.9   6.6   7.4   4.7   1.5   2.4   2.8   5.3   9.4  11.4 |   76.1
    >= 0.10         |   4.0   2.4   2.2   1.8   2.4   2.5   0.5   0.6   1.1   1.6   2.5   3.7 |   25.2
    >= 0.25         |   1.2   0.5   0.4   0.4   0.5   1.0   0.2   0.0   0.4   0.5   1.0   1.1 |    7.1
    >= 0.50         |   0.1   0.1   0.0   0.0   0.0   0.2   0.0   0.0   0.1   0.0   0.2   0.3 |    0.9
    >= 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|   6.4   6.3   7.5   7.2   7.5   7.6   6.3   6.0   5.3   5.7   5.9   5.9 |    6.5
Daily Avg Max 2-Min |  16.4  16.4  19.1  18.5  19.2  18.4  17.1  15.9  14.5  15.1  16.1  15.9 |   16.9
Daily Avg Peak Gust |  19.5  19.6  23.0  22.6  23.6  22.6  20.9  19.3  17.7  18.4  19.3  19.0 |   20.4
                    |                                                                         |
Maximum Daily Avg   |  24.4  23.9  23.7  21.9  17.7  18.7  16.2  16.5  19.9  20.3  20.8  22.7 |   24.4
                    |                                                                         |
Maximum 2-Minute Avg|    48    51    44    40    47    44    60    34    43    44    43    52 |     60
                    |                                                                         |
Date of Max 2min-Day|    12    07    13    27    19    30    07    10    25    28    20    01 |
               -Year|  2002  2002  2001  2004  2006  2008  2002  2000  2001  2003  1998  2001 |
                    |                                                                         |
Maximum Peak Gust   |    56    60    54    49    61    59    76    44    51    54    52    60 |     76
                    |                                                                         |
Date of Max Gust-Day|    12    07    13    27    19    30    07    10    25    28    20    01 |
               -Year|  2002  2002  2001  2004  2006  2008  2002  2000  2001  2003  1998  2001 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
   Peak Gust >=30   |   6.5   4.8   8.2   6.3   7.0   5.2   3.4   3.2   2.4   3.5   5.7   5.6 |   61.6
   Peak Gust >=40   |   1.5   1.6   1.8   0.9   0.8   0.7   0.7   0.3   0.4   0.8   1.7   2.1 |   13.3
   Peak Gust >=50   |   0.5   0.4   0.1   0.0   0.1   0.1   0.3   0.0   0.1   0.1   0.3   0.3 |    2.2
                    |                                                                         |
   Max 2-Minute >=30|   3.1   2.7   3.7   1.9   1.6   1.5   1.0   0.6   0.6   1.6   2.7   0.0 |   20.9
   Max 2-Minute >=40|   0.4   0.5   0.2   0.1   0.2   0.2   0.3   0.0   0.1   0.2   0.3   0.0 |    2.3
                    |                                                                         |
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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.