STATION:  ONTARIO INTERNATIONAL ARPT (KONT), CA

CLIMATOLOGICAL SUMMARY.  Period of Record: May 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        |  66.3  66.2  70.5  72.7  79.6  85.6  92.8  93.5  89.2  80.7  72.8  66.2 |   78.0
Avg Min Temp        |  43.4  44.7  47.4  49.6  55.2  59.0  64.0  64.2  61.1  55.4  48.4  42.6 |   52.9
Avg Temperature     |  54.9  55.5  58.9  61.1  67.4  72.3  78.4  78.8  75.1  68.0  60.6  54.4 |   65.5
                    |                                                                         |
Extremes:           |                                                                         |
    Extreme Max Temp|    90    89    94   101   103   108   114   109   110   101    94    86 |    114
                    |                                                                         |
    Date of Ext-Day |    31    22    11    26    28    20    22    30    01    20    07    24 |
               -Year|  2003  2002  2007  2004  2003  2008  2006  1998  2002  2003  2006  2005 |
                    |                                                                         |
    Extreme Min Temp|    25    31    33    33    42    46    56    56    52    44    32    28 |     25
                    |                                                                         |
    Date of Ext-Day |    14    03    12    10    01    05    12    08    28    18    30    22 |
               -Year|  2007  2002  2006  1999  1999  1999  2001  1999  1998  1998  2004  1998 |
                    |                                                                         |
Heating Degree Days |   317   273   205   152    38     9     0     0     2    38   157   331 |   1522
Cooling Degree Days |     3     4    17    36   113   227   413   427   302   131    25     2 |   1701
                    |                                                                         |
Avg Number of Days: |                                                                         |
    Max Temp >= 90  |   0.1   0.0   0.9   2.0   4.8  11.3  21.8  23.4  15.5   7.4   0.9   0.0 |   88.2
    Max Temp >= 75  |   6.6   5.6  10.2  12.0  21.1  26.2  31.0  30.9  27.9  21.1  12.6   6.3 |  211.5
    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  |   0.5   0.2   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.1   0.8 |    1.6
    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  |  36.5  39.5  42.9  45.1  51.2  55.3  58.7  57.5  54.5  47.7  41.6  34.9 |   47.1
Avg Wet Bulb Temp   |  46.5  47.8  50.6  52.4  57.6  61.4  65.4  65.0  62.1  56.6  51.0  45.8 |   55.2
                    |                                                                         |
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                    |                                                                         |
Avg Sea Level Pres  | 30.09 30.05 30.00 29.97 29.90 29.87 29.87 29.86 29.85 29.92 30.03 30.09 |  29.96
(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   0.8   0.8   0.4   0.3   0.0   0.5   0.2   0.3   0.3   0.3   0.2 |    4.1
    Heavy Fog       |   1.7   0.8   1.8   0.4   0.4   0.2   0.2   0.1   0.7   1.4   1.0   1.2 |    9.8
    Fog             |  13.7  13.8  17.3  14.6  16.6  18.0  13.9  12.2  12.6  16.2  14.0  10.9 |  173.8
    Hail            |   0.0   0.0   0.2   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0 |    0.2
                    |                                                                         |
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                    |                                                                         |
PRECIPITATION (In)  |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Average Monthly     |  2.17  3.50  1.19  1.12  0.19  0.02  0.01  0.04  0.07  0.55  0.78  1.27 |  10.92
                    |                                                                         |
Maximum Daily       |  3.23  2.94  2.53  1.22  0.43  0.24  0.03  0.30  0.29  1.37  1.61  1.70 |   3.23
                    |                                                                         |
    Date of Ext-Day |    09    12    15    04    22    02    05    15    20    27    30    15 |
               -Year|  2005  2001  2003  2006  2006  1999  2001  2005  2005  2004  2007  2008 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
    >= 0.01         |   5.1   6.9   4.9   4.2   1.0   0.4   0.5   0.4   0.7   1.9   3.5   5.2 |   34.6
    >= 0.10         |   3.5   5.4   2.5   2.2   0.6   0.1   0.0   0.2   0.3   0.7   1.5   2.5 |   19.5
    >= 0.25         |   2.2   3.9   1.2   1.4   0.3   0.0   0.0   0.1   0.1   0.6   1.0   1.5 |   12.4
    >= 0.50         |   1.4   2.5   0.6   1.0   0.0   0.0   0.0   0.0   0.0   0.5   0.4   0.7 |    7.0
    >= 1.00         |   0.7   1.0   0.2   0.2   0.0   0.0   0.0   0.0   0.0   0.2   0.3   0.4 |    2.9
                    |                                                                         |
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                    |                                                                         |
WIND (MPH)          |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Daily Avg Wind Speed|   5.5   5.5   6.3   6.7   7.1   7.0   6.8   6.4   5.8   5.4   4.9   5.1 |    6.0
Daily Avg Max 2-Min |  16.6  15.9  17.7  17.6  17.7  17.4  17.6  17.5  16.6  15.9  14.8  14.9 |   16.7
Daily Avg Peak Gust |  20.7  19.8  22.1  22.1  22.4  22.0  22.3  22.1  20.9  19.8  18.3  18.9 |   20.9
                    |                                                                         |
Maximum Daily Avg   |  34.0  23.0  29.9  14.8  16.1  10.3   9.8   9.0  20.1  26.6  24.3  36.8 |   36.8
                    |                                                                         |
Maximum 2-Minute Avg|    68    41    51    31    36    28    30    36    32    48    43    60 |     68
                    |                                                                         |
Date of Max 2min-Day|    06    09    21    01    03    27    17    31    21    22    26    09 |
               -Year|  2003  2002  2000  2000  2001  2006  2003  1998  2004  2007  2002  1998 |
                    |                                                                         |
Maximum Peak Gust   |    90    53    62    44    46    32    35    44    52    66    58    72 |     90
                    |                                                                         |
Date of Max Gust-Day|    06    09    21    05    03    27    17    31    02    22    29    09 |
               -Year|  2003  2002  2000  2006  2001  2006  2003  1998  2007  2007  2006  1998 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
   Peak Gust >=30   |   5.4   3.4   3.5   1.7   0.7   0.1   0.4   0.2   0.5   2.4   3.0   4.9 |   26.2
   Peak Gust >=40   |   3.5   1.2   1.5   0.2   0.1   0.0   0.0   0.1   0.2   1.0   1.5   1.9 |   11.3
   Peak Gust >=50   |   1.5   0.3   0.7   0.0   0.0   0.0   0.0   0.0   0.1   0.3   0.5   0.9 |    4.3
                    |                                                                         |
   Max 2-Minute >=30|   3.5   1.6   1.8   0.2   0.1   0.0   0.1   0.1   0.2   1.3   1.7   0.0 |   10.7
   Max 2-Minute >=40|   1.2   0.2   0.4   0.0   0.0   0.0   0.0   0.0   0.0   0.3   0.5   0.0 |    2.6
                    |                                                                         |
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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.