STATION:  ST JOHNS INDUS AIRPK ARPT (KSJN), AZ

CLIMATOLOGICAL SUMMARY.  Period of Record: May 1999 to Dec 2008

Summaries based on unedited daily ASOS data.  Errors may be present.

-----------------------------------------------------------------------------------------------

TEMPERATURE (F)     |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Avg Max Temp        |  51.6  55.4  62.6  71.9  82.3  90.9  92.3  87.9  83.5  72.7  60.7  49.4 |   71.8
Avg Min Temp        |  21.6  24.5  29.5  37.4  46.8  55.1  62.4  60.0  51.8  39.4  27.5  19.6 |   39.6
Avg Temperature     |  36.6  39.9  46.1  54.6  64.5  73.0  77.3  73.9  67.6  56.1  44.1  34.5 |   55.7
                    |                                                                         |
Extremes:           |                                                                         |
    Extreme Max Temp|    72    74    87    88    99   101   107   101    95    92    82    72 |    107
                    |                                                                         |
    Date of Ext-Day |    16    01    20    28    20    20    18    10    28    01    10    01 |
               -Year|  2000  2003  2004  2007  2005  2005  2005  2003  2003  2003  2005  2003 |
                    |                                                                         |
    Extreme Min Temp|    -2    -1    -2    21    23    36    48    45    31    18    -2    -6 |     -6
                    |                                                                         |
    Date of Ext-Day |    31    01    13    08    02    15    02    25    25    13    30    13 |
               -Year|  2002  2002  2006  2003  2008  2001  2004  2002  2000  2008  2006  2001 |
                    |                                                                         |
Heating Degree Days |   881   708   587   312    93     6     0     0    28   285   627   945 |   4474
Cooling Degree Days |     0     0     0     1    78   246   383   278   106     8     0     0 |   1100
                    |                                                                         |
Avg Number of Days: |                                                                         |
    Max Temp >= 90  |   0.0   0.0   0.0   0.0   5.1  19.4  20.7  12.1   3.8   0.1   0.0   0.0 |   61.2
    Max Temp >= 75  |   0.1   0.0   3.6  13.7  26.0  29.5  31.0  30.8  28.3  14.6   1.8   0.0 |  179.3
    Max Temp <= 32  |   0.9   0.2   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.2   1.8 |    3.1
                    |                                                                         |
    Min Temp <= 32  |  27.1  22.8  19.7   7.4   1.1   0.0   0.0   0.0   0.1   6.3  21.7  29.3 |  135.5
    Min Temp <= 20  |  13.9   8.9   4.3   0.0   0.0   0.0   0.0   0.0   0.0   0.5   6.2  17.3 |   51.0
    Min Temp  <= 0  |   0.1   0.2   0.1   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.1   0.4 |    0.9
                    |                                                                         |
Avg Dew Point Temp  |  18.7  18.1  19.6  19.9  24.9  30.0  46.7  50.9  40.3  30.7  20.5  17.3 |   28.1
Avg Wet Bulb Temp   |  29.4  31.6  35.7  40.3  46.4  51.8  59.3  59.7  53.0  44.0  34.4  27.8 |   42.8
                    |                                                                         |
------------------------------------------------------------------------------------------------------
                    |                                                                         |
Avg Sea Level Pres  | 30.12 30.04 29.97 29.89 29.83 29.81 29.87 29.91 29.91 29.97 30.07 30.13 |  29.96
(Inches of Mercury) |                                                                         |
------------------------------------------------------------------------------------------------------
                    |                                                                         |
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   0.9   2.1   2.4   3.4   8.8  10.3   4.0   3.2   0.4   0.0 |   36.0
    Heavy Fog       |   1.9   0.9   1.0   0.1   0.0   0.0   0.0   0.0   0.0   0.1   0.4   1.5 |    5.9
    Fog             |   7.9   3.2   4.0   1.7   0.5   0.1   2.0   1.7   1.8   2.4   2.5   6.5 |   34.4
    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
                    |                                                                         |
------------------------------------------------------------------------------------------------------
                    |                                                                         |
PRECIPITATION (In)  |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Average Monthly     |  0.31  0.45  0.45  0.34  0.26  0.13  1.32  1.81  0.80  0.81  0.39  0.42 |   7.48
                    |                                                                         |
Maximum Daily       |  0.44  0.34  0.72  0.38  0.64  0.19  1.03  2.47  1.14  0.80  0.39  0.42 |   2.47
                    |                                                                         |
    Date of Ext-Day |    28    12    11    24    22    28    12    04    10    23    04    01 |
               -Year|  2008  2005  2006  2005  2008  2004  2008  2007  2002  2000  2000  2007 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
    >= 0.01         |   4.7   4.4   4.6   3.2   2.0   2.4   9.0  11.2   5.1   5.7   3.2   5.0 |   60.5
    >= 0.10         |   0.9   1.4   1.5   1.2   0.9   0.5   4.2   4.1   2.2   2.8   1.4   1.4 |   22.5
    >= 0.25         |   0.2   0.7   0.6   0.6   0.4   0.0   1.8   2.5   1.0   1.3   0.5   0.5 |   10.0
    >= 0.50         |   0.0   0.0   0.1   0.0   0.1   0.0   0.3   0.6   0.4   0.2   0.0   0.0 |    1.7
    >= 1.00         |   0.0   0.0   0.0   0.0   0.0   0.0   0.1   0.2   0.1   0.0   0.0   0.0 |    0.4
                    |                                                                         |
------------------------------------------------------------------------------------------------------
                    |                                                                         |
WIND (MPH)          |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Daily Avg Wind Speed|   6.3   7.6   8.5  10.3   9.4   9.2   7.6   6.4   6.7   6.4   6.1   6.0 |    7.5
Daily Avg Max 2-Min |  17.9  21.4  22.9  27.0  26.1  26.2  25.6  22.9  21.4  18.9  17.5  17.6 |   22.1
Daily Avg Peak Gust |  21.7  26.5  28.9  34.0  33.1  33.3  31.8  28.2  27.0  23.7  21.5  21.4 |   27.6
                    |                                                                         |
Maximum Daily Avg   |  22.0  24.1  25.5  23.4  23.6  24.7  12.7  12.1  18.7  22.9  26.0  24.8 |   26.0
                    |                                                                         |
Maximum 2-Minute Avg|    45    52    45    52    49    49    48    40    46    41    49    45 |     52
                    |                                                                         |
Date of Max 2min-Day|    28    03    30    29    18    16    31    16    10    11    22    01 |
               -Year|  2008  2008  2008  2004  2002  2000  2001  2008  2002  2008  2003  2007 |
                    |                                                                         |
Maximum Peak Gust   |    58    64    62    62    62    61    62    52    56    60    60    59 |     64
                    |                                                                         |
Date of Max Gust-Day|    28    03    18    30    18    16    08    14    10    11    25    25 |
               -Year|  2008  2008  2006  2008  2002  2000  2005  2007  2002  2008  2001  2008 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
   Peak Gust >=30   |   6.9  10.6  13.7  19.0  20.3  21.5  17.8  12.6  10.8   7.8   5.1   6.9 |  153.0
   Peak Gust >=40   |   2.3   3.5   4.8   8.7   6.3   4.7   4.9   1.7   2.3   1.5   2.0   3.2 |   46.0
   Peak Gust >=50   |   0.5   0.9   0.9   2.0   0.8   0.8   0.8   0.2   0.1   0.3   0.6   0.7 |    8.5
                    |                                                                         |
   Max 2-Minute >=30|   3.6   5.4   6.5  11.3   9.9   7.4   8.3   4.0   3.0   2.9   2.8   0.0 |   65.2
   Max 2-Minute >=40|   0.3   0.9   0.7   2.2   1.0   0.6   1.1   0.1   0.1   0.2   0.8   0.0 |    8.0
                    |                                                                         |
------------------------------------------------------------------------------------------------------

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.