STATION:  CHINO AIRPORT (KCNO), CA

CLIMATOLOGICAL SUMMARY.  Period of Record: Apr 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        |  67.8  67.3  70.6  73.5  79.9  85.8  92.8  93.8  90.0  82.0  74.2  67.8 |   78.8
Avg Min Temp        |  38.7  40.6  43.0  45.4  51.7  55.6  60.1  60.0  56.5  50.5  43.2  37.7 |   48.6
Avg Temperature     |  53.3  54.0  56.8  59.4  65.8  70.7  76.5  76.9  73.2  66.2  58.7  52.7 |   63.7
                    |                                                                         |
Extremes:           |                                                                         |
    Extreme Max Temp|    92    90    97   108   103   109   114   109   112   103    95    86 |    114
                    |                                                                         |
    Date of Ext-Day |    31    22    12    02    03    20    22    29    03    21    07    24 |
               -Year|  2003  2002  2007  1998  2004  2008  2006  1998  2007  2003  2006  2005 |
                    |                                                                         |
    Extreme Min Temp|    20    27    28    31    32    38    50    51    47    39    27    23 |     20
                    |                                                                         |
    Date of Ext-Day |    14    01    03    02    30    19    17    08    20    18    13    24 |
               -Year|  2007  2002  2002  1999  2002  2002  2000  1999  1999  1998  2000  1998 |
                    |                                                                         |
Heating Degree Days |   364   312   261   186    49     9     0     0     3    48   199   381 |   1812
Cooling Degree Days |     1     1     6    19    74   178   355   368   250    86     9     1 |   1348
                    |                                                                         |
Avg Number of Days: |                                                                         |
    Max Temp >= 90  |   0.1   0.1   0.6   2.0   4.6  11.2  22.1  23.6  16.2   8.0   1.4   0.0 |   89.9
    Max Temp >= 75  |   7.5   6.2   9.8  11.7  22.0  26.7  31.0  30.9  28.6  22.7  14.6   7.4 |  219.2
    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  |   4.2   2.2   0.9   0.2   0.1   0.0   0.0   0.0   0.0   0.0   1.0   5.8 |   14.4
    Min Temp <= 20  |   0.1   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0 |    0.1
    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  |  38.0  40.4  44.3  46.2  51.4  55.5  59.2  58.8  55.6  48.8  42.9  36.8 |   48.2
Avg Wet Bulb Temp   |  46.0  47.4  50.2  52.1  57.1  61.0  64.5  64.8  61.7  56.1  50.3  45.2 |   54.7
                    |                                                                         |
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                    |                                                                         |
Avg Sea Level Pres  | 30.11 30.07 30.02 29.99 29.94 29.90 29.91 29.90 29.88 29.95 30.05 30.11 |  29.99
(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   |   1.3   1.0   1.4   0.7   0.5   0.8   1.2   0.4   1.1   0.9   0.7   0.3 |   10.3
    Heavy Fog       |   7.5   4.5   7.5   4.2   2.9   2.5   1.6   1.3   4.0   7.1   7.0   4.7 |   54.8
    Fog             |  22.0  20.9  24.3  23.8  23.8  24.5  22.0  23.9  23.1  23.3  20.8  19.0 |  271.3
    Hail            |   0.0   0.0   0.1   0.1   0.0   0.0   0.0   0.0   0.0   0.1   0.0   0.0 |    0.3
                    |                                                                         |
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                    |                                                                         |
PRECIPITATION (In)  |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Average Monthly     |  1.59  2.86  0.97  0.92  0.10  0.04  0.03  0.00  0.05  0.89  0.59  0.85 |   8.89
                    |                                                                         |
Maximum Daily       |  2.97  2.65  1.64  1.11  0.48  0.25  0.18  0.03  0.18  2.62  1.16  1.74 |   2.97
                    |                                                                         |
    Date of Ext-Day |    09    12    15    04    22    02    05    31    20    20    30    15 |
               -Year|  2005  2001  2003  2006  2006  1999  2001  1998  2005  2004  2007  2008 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
    >= 0.01         |   5.1   7.1   5.3   4.8   1.0   0.5   0.3   0.2   0.9   4.3   5.4   4.5 |   39.4
    >= 0.10         |   2.5   4.7   2.5   2.0   0.2   0.2   0.1   0.0   0.3   1.0   1.2   2.0 |   16.6
    >= 0.25         |   1.8   3.3   0.9   1.5   0.1   0.1   0.0   0.0   0.0   0.8   0.7   1.2 |   10.4
    >= 0.50         |   1.0   1.8   0.5   0.6   0.0   0.0   0.0   0.0   0.0   0.6   0.5   0.4 |    5.4
    >= 1.00         |   0.5   0.8   0.2   0.1   0.0   0.0   0.0   0.0   0.0   0.4   0.1   0.2 |    2.2
                    |                                                                         |
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                    |                                                                         |
WIND (MPH)          |   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec |   Year
                    |                                                                         |
Daily Avg Wind Speed|   4.5   4.8   5.4   6.1   6.7   6.7   6.3   5.8   5.0   4.6   4.0   4.1 |    5.3
Daily Avg Max 2-Min |  15.2  15.7  17.0  18.1  18.7  18.3  18.1  17.6  16.8  15.7  14.4  14.0 |   16.6
Daily Avg Peak Gust |  18.7  19.1  20.9  22.0  22.6  22.1  21.9  21.5  20.4  19.3  17.9  17.5 |   20.3
                    |                                                                         |
Maximum Daily Avg   |  27.1  19.4  20.2  11.8  13.0  11.0   9.9   8.4  12.4  19.7  15.9  21.3 |   27.1
                    |                                                                         |
Maximum 2-Minute Avg|    51    37    35    36    30    30    23    23    31    36    35    40 |     51
                    |                                                                         |
Date of Max 2min-Day|    06    09    31    28    03    27    16    09    02    13    25    09 |
               -Year|  2003  2002  2005  1999  2001  2006  2001  1999  1998  2008  2002  1998 |
                    |                                                                         |
Maximum Peak Gust   |    62    52    47    45    41    35    30    30    37    58    58    63 |     63
                    |                                                                         |
Date of Max Gust-Day|    06    09    21    01    03    27    22    30    02    21    25    09 |
               -Year|  2003  2002  2000  2000  2001  2006  2006  2007  1998  2007  2002  1998 |
                    |                                                                         |
Avg Number of Days: |                                                                         |
   Peak Gust >=30   |   4.0   2.0   2.3   1.6   0.9   0.2   0.1   0.1   0.4   1.6   2.5   3.8 |   19.4
   Peak Gust >=40   |   1.6   0.6   0.7   0.3   0.1   0.0   0.0   0.0   0.0   0.5   0.6   1.3 |    5.6
   Peak Gust >=50   |   0.2   0.1   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.3   0.1   0.2 |    0.9
                    |                                                                         |
   Max 2-Minute >=30|   1.5   0.4   0.7   0.3   0.1   0.1   0.0   0.0   0.1   0.4   0.5   0.0 |    4.0
   Max 2-Minute >=40|   0.2   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0 |    0.2
                    |                                                                         |
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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.