STATION:  GUAM INTL AIRPORT (PGUM), PI

CLIMATOLOGICAL SUMMARY.  Period of Record: Jul 1996 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        |  85.8  85.8  86.7  88.0  88.1  87.7  87.2  86.7  86.8  87.3  87.1  86.5 |   87.0
Avg Min Temp        |  75.4  75.4  75.9  77.0  77.5  77.5  76.7  76.3  75.9  76.8  77.0  76.7 |   76.5
Avg Temperature     |  80.6  80.6  81.3  82.5  82.8  82.6  81.9  81.5  81.3  82.0  82.1  81.6 |   81.7
                    |                                                                         |
Extremes:           |                                                                         |
    Extreme Max Temp|    89    89    92    92    92    92    92    91    91    91    90    89 |     92
                    |                                                                         |
    Date of Ext-Day |    03    23    31    30    30    02    11    27    01    02    03    06 |
               -Year|  2008  2001  2006  2006  1997  2001  1996  1999  1996  2001  1996  1998 |
                    |                                                                         |
    Extreme Min Temp|    66    68    70    71    72    72    71    72    71    72    71    71 |     66
                    |                                                                         |
    Date of Ext-Day |    18    24    17    06    02    23    09    08    16    16    07    02 |
               -Year|  2000  2003  1997  2002  1998  1997  2006  1996  1996  1999  2001  2003 |
                    |                                                                         |
Heating Degree Days |     0     0     0     0     0     0     0     0     0     0     0     0 |      0
Cooling Degree Days |   483   440   505   525   552   529   524   511   490   528   513   515 |   6115
                    |                                                                         |
Avg Number of Days: |                                                                         |
    Max Temp >= 90  |   0.0   0.0   0.1   3.4   4.2   5.2   2.2   2.1   1.2   2.3   1.6   0.0 |   22.2
    Max Temp >= 75  |  31.0  28.2  31.0  30.0  31.0  30.0  31.0  31.0  30.0  31.0  30.0  31.0 |  365.2
    Max Temp <= 32  |   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
                    |                                                                         |
    Min Temp <= 32  |   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
    Min Temp <= 20  |   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
    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  |  71.8  72.3  72.3  73.7  74.5  75.2  75.4  75.4  75.2  75.2  75.2  73.9 |   74.2
Avg Wet Bulb Temp   |  74.2  74.6  74.9  76.2  76.7  77.3  77.1  77.1  76.8  76.9  77.2  76.1 |   76.3
                    |                                                                         |
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                    |                                                                         |
Avg Sea Level Pres  | 29.87 29.87 29.87 29.86 29.85 29.85 29.83 29.81 29.81 29.81 29.81 29.85 |  29.84
(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   |   0.2   0.2   0.0   0.2   1.3   2.6   4.9   5.6   5.4   3.6   1.9   0.6 |   26.4
    Heavy Fog       |   0.0   0.0   0.0   0.0   0.2   0.4   0.5   0.3   0.5   0.3   0.1   0.2 |    2.5
    Fog             |  10.3  10.9  10.2   9.5  10.7  12.6  12.1  11.4  10.2  11.4  11.2  11.1 |  131.7
    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     |  4.25  4.93  2.68  2.46  3.88  8.98 12.71 16.88 14.06 10.63  9.29  7.47 |  98.22
                    |                                                                         |
Maximum Daily       |  2.29  3.60  2.03  2.89  2.26  6.00  9.35  7.52  4.93  5.43  4.69 13.81 |  13.81
                    |                                                                         |
    Date of Ext-Day |    08    14    11    30    24    27    05    22    26    18    16    16 |
               -Year|  2002  1999  2003  2003  2007  2004  2002  2004  2002  2003  2003  1997 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
    >= 0.01         |  19.2  18.6  17.8  18.4  20.8  24.6  25.8  25.6  24.6  25.5  24.4  22.8 |  268.1
    >= 0.10         |   9.8   9.8   7.5   7.2   9.8  15.8  18.3  18.7  18.0  17.5  15.2  11.7 |  159.2
    >= 0.25         |   4.4   4.6   2.8   2.5   4.1   8.4  12.5  14.0  13.6  11.6  10.4   6.5 |   95.4
    >= 0.50         |   2.4   2.6   1.2   0.5   1.8   5.2   7.4   9.2   9.0   6.5   5.7   2.9 |   54.4
    >= 1.00         |   0.8   0.9   0.2   0.2   0.5   2.0   3.8   5.4   4.4   2.5   2.6   1.2 |   24.4
                    |                                                                         |
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                    |                                                                         |
WIND (MPH)          |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Daily Avg Wind Speed|  12.2  12.1  11.8  11.1   9.5   8.9   7.2   6.9   5.8   7.2  10.7  11.8 |    9.6
Daily Avg Max 2-Min |  20.3  20.4  19.8  19.2  17.3  17.2  16.1  16.1  15.0  16.4  19.5  20.3 |   18.1
Daily Avg Peak Gust |  25.2  25.6  24.8  24.3  22.2  22.1  21.1  21.0  19.8  21.4  24.8  25.4 |   23.1
                    |                                                                         |
Maximum Daily Avg   |  19.7  22.1  20.6  22.0  16.6  31.4  32.1  27.5  15.0  18.5  23.0  40.8 |   40.8
                    |                                                                         |
Maximum 2-Minute Avg|    34    32    35    32    37    47    74    52    36    32    49    58 |     74
                    |                                                                         |
Date of Max 2min-Day|    24    12    02    15    16    28    05    22    01    18    08    16 |
               -Year|  2000  2004  2002  2003  2002  2004  2002  2004  2005  2003  1996  1997 |
                    |                                                                         |
Maximum Peak Gust   |    41    38    40    41    44    58    90    66    44    43    61    94 |     94
                    |                                                                         |
Date of Max Gust-Day|    23    28    02    15    16    28    05    22    01    28    08    16 |
               -Year|  2000  2001  2002  2003  2002  2004  2002  2004  2005  2000  1996  1997 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
   Peak Gust >=30   |   7.9   7.6   5.3   3.6   0.9   2.2   2.6   3.5   1.9   2.9   6.1   7.2 |   51.7
   Peak Gust >=40   |   0.2   0.0   0.2   0.2   0.1   0.2   0.8   0.6   0.1   0.2   1.0   0.4 |    3.8
   Peak Gust >=50   |   0.0   0.0   0.0   0.0   0.0   0.1   0.2   0.2   0.0   0.0   0.3   0.1 |    0.9
                    |                                                                         |
   Max 2-Minute >=30|   0.5   0.9   0.7   0.6   0.3   0.3   0.7   0.6   0.2   0.3   1.3   0.0 |    6.4
   Max 2-Minute >=40|   0.0   0.0   0.0   0.0   0.0   0.2   0.2   0.2   0.0   0.0   0.1   0.0 |    0.6
                    |                                                                         |
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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.