STATION:  GRAND CANYON NATL PARK APT (KGCN), AZ

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        |  44.4  46.1  54.3  60.3  72.5  82.3  86.0  82.4  75.9  64.8  53.9  44.4 |   64.0
Avg Min Temp        |  14.7  16.8  20.4  24.7  30.8  36.9  48.5  48.4  39.6  28.7  20.3  13.2 |   28.6
Avg Temperature     |  29.6  31.4  37.4  42.5  51.6  59.6  67.3  65.4  57.8  46.8  37.1  28.8 |   46.3
                    |                                                                         |
Extremes:           |                                                                         |
    Extreme Max Temp|    61    66    77    81    91    93    99    94    87    84    73    66 |     99
                    |                                                                         |
    Date of Ext-Day |    06    28    21    27    28    28    11    11    14    01    05    04 |
               -Year|  1999  1999  2004  2000  2000  1998  2003  2003  2000  2003  2001  2007 |
                    |                                                                         |
    Extreme Min Temp|   -17   -17    -8     7    14    25    30    31    22     6    -8   -19 |    -19
                    |                                                                         |
    Date of Ext-Day |    03    05    01    01    12    10    01    24    24    22    30    27 |
               -Year|  2000  2008  1997  1999  2000  2004  2004  2002  2000  1996  2006  2008 |
                    |                                                                         |
Heating Degree Days |  1099   948   857   675   414   166    18    32   219   565   838  1122 |   6953
Cooling Degree Days |     0     0     0     0     0     6    89    44     2     0     0     0 |    141
                    |                                                                         |
Avg Number of Days: |                                                                         |
    Max Temp >= 90  |   0.0   0.0   0.0   0.0   0.4   2.9   9.2   2.7   0.0   0.0   0.0   0.0 |   15.3
    Max Temp >= 75  |   0.2   0.0   0.3   0.9  14.5  25.8  30.0  29.1  19.1   4.8   0.0   0.0 |  124.6
    Max Temp <= 32  |   3.4   1.7   0.5   0.2   0.0   0.0   0.0   0.0   0.0   0.0   0.8   3.1 |    9.6
                    |                                                                         |
    Min Temp <= 32  |  30.1  27.7  30.3  27.2  19.2   6.7   0.4   0.1   5.1  22.7  28.4  30.1 |  227.9
    Min Temp <= 20  |  21.2  17.3  13.8   7.2   1.4   0.0   0.0   0.0   0.0   3.5  15.2  23.2 |  102.8
    Min Temp  <= 0  |   3.4   2.1   0.8   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.6   3.2 |   10.1
                    |                                                                         |
Avg Dew Point Temp  |  17.0  17.4  19.1  20.4  23.1  24.8  41.1  45.7  36.0  25.9  18.9  14.8 |   25.4
Avg Wet Bulb Temp   |  25.0  26.5  30.3  34.0  39.9  44.5  53.2  54.2  46.8  37.5  29.5  23.5 |   37.1
                    |                                                                         |
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                    |                                                                         |
Avg Sea Level Pres  | 30.16 30.10 30.04 29.97 29.93 29.92 29.98 30.01 29.99 30.06 30.14 30.17 |  30.04
(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   |   0.1   0.3   0.8   0.9   1.8   2.5   8.7  10.8   5.3   1.9   0.4   0.1 |   33.7
    Heavy Fog       |   4.6   3.8   3.2   2.8   0.1   0.0   0.7   0.2   0.2   0.9   1.6   2.2 |   20.4
    Fog             |   8.5   9.3   7.6   6.0   1.5   1.3   4.1   4.8   3.8   5.8   5.5   6.5 |   64.5
    Hail            |   0.2   0.2   0.1   0.2   0.2   0.0   0.3   0.8   0.2   0.3   0.1   0.0 |    2.5
                    |                                                                         |
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                    |                                                                         |
PRECIPITATION (In)  |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Average Monthly     |  1.17  1.09  1.05  0.79  0.37  0.41  1.90  2.20  1.50  1.40  0.84  0.69 |  13.41
                    |                                                                         |
Maximum Daily       |  0.82  0.86  0.96  1.07  0.90  0.64  1.21  1.63  2.64  2.32  1.42  1.17 |   2.64
                    |                                                                         |
    Date of Ext-Day |    05    11    23    24    20    02    14    16    19    21    08    01 |
               -Year|  2008  2005  2007  2005  1998  1999  1999  1999  2004  2004  2004  2007 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
    >= 0.01         |   7.1   7.3   6.2   6.0   2.5   2.5  10.7  12.3   7.5   5.2   4.1   5.7 |   77.1
    >= 0.10         |   3.7   3.6   3.5   2.5   1.2   1.0   4.7   5.6   3.4   2.9   2.0   1.9 |   36.0
    >= 0.25         |   1.8   1.4   1.4   0.8   0.3   0.7   2.6   2.5   1.7   1.5   0.9   0.7 |   16.6
    >= 0.50         |   0.7   0.3   0.3   0.3   0.2   0.3   1.1   1.2   0.9   1.0   0.5   0.2 |    6.9
    >= 1.00         |   0.0   0.0   0.0   0.1   0.0   0.0   0.2   0.4   0.1   0.2   0.1   0.1 |    1.1
                    |                                                                         |
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                    |                                                                         |
WIND (MPH)          |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Daily Avg Wind Speed|   6.0   6.5   6.5   7.9   7.3   7.4   5.2   4.7   5.7   5.9   5.5   5.8 |    6.2
Daily Avg Max 2-Min |  16.8  18.4  19.5  22.7  22.3  22.9  19.7  18.6  19.6  18.4  17.3  16.7 |   19.4
Daily Avg Peak Gust |  21.3  23.7  25.4  29.7  29.6  30.7  26.2  24.4  25.9  24.2  22.0  21.6 |   25.4
                    |                                                                         |
Maximum Daily Avg   |  19.4  21.5  19.6  22.2  23.4  19.1  12.5  12.2  19.6  21.8  18.5  23.5 |   23.5
                    |                                                                         |
Maximum 2-Minute Avg|    44    46    41    45    41    44    35    33    37    46    40    44 |     46
                    |                                                                         |
Date of Max 2min-Day|    28    15    31    15    10    09    03    06    19    30    25    13 |
               -Year|  2008  2006  1999  2002  2000  2002  2000  2008  2004  2003  2001  2008 |
                    |                                                                         |
Maximum Peak Gust   |    59    60    54    59    53    55    48    47    48    58    46    62 |     62
                    |                                                                         |
Date of Max Gust-Day|    28    15    31    15    10    09    01    15    09    30    17    13 |
               -Year|  2008  2006  1999  2002  2000  2004  2001  2007  2005  2003  1999  2008 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
   Peak Gust >=30   |   4.7   6.0   7.8  13.8  14.5  16.5   8.0   5.9   8.6   6.2   4.8   4.8 |  101.6
   Peak Gust >=40   |   0.5   1.2   1.6   4.2   3.1   2.8   0.6   0.3   1.6   1.3   0.5   1.4 |   19.2
   Peak Gust >=50   |   0.1   0.2   0.2   0.4   0.3   0.3   0.0   0.0   0.0   0.3   0.0   0.2 |    1.9
                    |                                                                         |
   Max 2-Minute >=30|   1.1   1.6   2.1   5.0   3.8   3.5   0.6   0.6   1.9   1.5   1.2   0.0 |   22.9
   Max 2-Minute >=40|   0.1   0.1   0.1   0.3   0.2   0.1   0.0   0.0   0.0   0.2   0.1   0.0 |    1.0
                    |                                                                         |
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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.