National Weather Service Weather Forecast Office

Climatological Report (Monthly)
Issued by NWS Denver/Boulder, CO

000
CXUS55 KBOU 011513
CLMDEN

CLIMATE REPORT
NATIONAL WEATHER SERVICE BOULDER, CO
907 AM MDT SAT SEP 1 2012

...AUGUST 2012...5TH WARMEST AND 4TH DRIEST AUGUST ON RECORD...

THE HOT SUMMER OF 2012 CONTINUED THROUGH AUGUST AS A STRONG AND
PERSISTENT SUBTROPICAL HIGH PRESSURE RIDGE DOMINATED THE ROCKY
MOUNTAIN REGION. THE MONTH GOT OFF TO A HOT START WITH TEN OF THE
FIRST ELEVEN DAYS ABOVE 90 DEGREES. A COLD FRONT BROUGHT COOLER
TEMPERATURES TO DENVER ON THE 12TH AND 13TH...WITH HIGH TEMPERATURES
OF 86 AND 79 DEGREES RESPECTIVELY. TEMPERATURES REBOUNDED INTO THE
MID 90S ON THE 14TH. THE UPPER RIDGE OF HIGH PRESSURE THEN SHIFTED
WESTWARD OVER THE WESTERN UNITED STATES AS A LARGE UPPER LEVEL LOW
PRESSURE TROUGH DEEPENED OVER THE UPPER MIDWEST. THIS PATTERN PUT
COLORADO INTO A NORTHWESTERLY FLOW ALOFT...WHICH ALLOWED A COUPLE OF
WEAK COLD FRONTS TO BRUSH NORTHEASTERN COLORADO. AS A RESULT...BELOW
AVERAGE TEMPERATURES WERE RECORDED AT DENVER INTERNATIONAL AIRPORT
FROM THE 16TH THROUGH THE 20TH. ABOVE AVERAGE TEMPERATURES RETURNED
TO THE FRONT RANGE ON THE 21ST AS THE UPPER RIDGE SHIFTED EASTWARD
OVER THE ROCKY MOUNTAIN REGION. THE ABNORMALLY WARM TEMPERATURES
CONTINUED THROUGH THE END OF THE MONTH...WITH THE EXCEPTION OF THE
25TH...WHEN A WEAK COLD FRONT MOVED ACROSS THE AREA. AUGUST 2012 WAS
ALSO ABNORMALLY DRY WITH ONLY ONE DAY OF MEASURABLE PRECIPITATION. A
SCANT 0.11 INCHES OF PRECIPITATION WAS RECORDED DURING THE MONTH.

TEMPERATURES:

THE AVERAGE TEMPERATURE FOR THE MONTH OF AUGUST WAS 75.0 DEGREES
WHICH WAS 2.5 DEGREES ABOVE NORMAL...MAKING IT THE 5TH WARMEST SINCE
RECORDS BEGAN IN 1872...AND TYING AUGUST OF 1994. AUGUST 2011
REMAINS THE WARMEST AUGUST ON RECORD WITH AN AVERAGE TEMPERATURE OF
77.0 DEGREES.

THERE WERE 20 DAYS IN WHICH THE MAXIMUM TEMPERATURE EXCEEDED 90
DEGREES. THE HIGHEST TEMPERATURE OF THE MONTH WAS 98 DEGREES WHICH
OCCURRED ON THE 3RD...6TH...9TH AND THE 27TH. THE COOLEST
TEMPERATURE OF THE MONTH WAS 47 DEGREES ON THE MORNING OF THE 17TH.

BELOW IS LIST OF TEMPERATURE RECORDS FOR AUGUST 2012:

DAILY RECORDS:

  DATE       TEMPERATURE   TYPE OF RECORD    OLD RECORD   YEAR SET
AUGUST  9TH   98 DEGREES   TIED RECORD MAX   98 DEGREES     2000
AUGUST 27TH   98 DEGREES   TIED RECORD MAX   98 DEGREES     1994
AUGUST 28TH   96 DEGREES   TIED RECORD MAX   96 DEGREES     2011
AUGUST 29TH   97 DEGREES    NEW RECORD MAX   96 DEGREES     1900

PRECIPITATION.

PRECIPITATION FOR THE MONTH OF AUGUST WAS 0.11 INCHES...WHICH IS
1.58 INCHES BELOW THE NORMAL 0F 1.68 INCHES...MAKING THIS THE 4TH
DRIEST AUGUST ON RECORD IN DENVER. ALL OF THIS PRECIPITATION FELL ON
THE 11TH...WITH TRACE AMOUNTS RECORDED EIGHT OTHER DAYS. THE DRIEST
AUGUST ON RECORD OCCURRED BACK IN 1924 WHEN ONLY 0.02 INCHES OF RAIN
FELL.

THERE WERE 4 THUNDERSTORMS OBSERVED AT DENVER INTERNATIONAL
AIRPORT...WITH NO DENSE FOG WITH A VISIBILITY AT OR BELOW 1/4 MILE
DURING THE MONTH. A PEAK WIND OF 45 MPH FROM A NORTHWEST DIRECTION
WAS RECORDED ON THE 30TH.
...................................

...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF AUGUST 2012...

CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2012

WEATHER         OBSERVED          NORMAL  DEPART  LAST YEAR`S
                 VALUE   DATE(S)  VALUE   FROM    VALUE  DATE(S)
                                          NORMAL
................................................................
TEMPERATURE (F)
RECORD
 HIGH             105   08/08/1878
 LOW               40   08/26/1910
                        08/25/1910
                        08/24/1910
HIGHEST            98   08/27        87      11       99  08/25
                        08/03
                        08/06
                        08/09
LOWEST             47   08/17        40       7       55  08/20
AVG. MAXIMUM     91.0              87.2     3.8     92.7
AVG. MINIMUM     58.9              57.9     1.0     61.3
MEAN             75.0              72.5     2.5     77.0
DAYS MAX >= 90     20              11.5     8.5       22
DAYS MAX <= 32      0               0.0     0.0        0
DAYS MIN <= 32      0               0.0     0.0        0
DAYS MIN <= 0       0               0.0     0.0        0

PRECIPITATION (INCHES)
RECORD
 MAXIMUM         5.85   1979
 MINIMUM         0.02   1924
TOTALS           0.11              1.69   -1.58     0.30
DAILY AVG.       0.00              0.05   -0.05     0.01
DAYS >= .01         1               8.6    -7.6        3
DAYS >= .10         1               4.3    -3.3        1
DAYS >= .50         0               1.2    -1.2        0
DAYS >= 1.00        0               0.3    -0.3        0
GREATEST
 24 HR. TOTAL    0.11   08/11 TO 08/11           08/03 TO 08/03

SNOWFALL (INCHES)
RECORDS
 TOTAL            0.0  NO SNOW EVER RECORDED IN AUGUST
TOTALS            0.0  NO SNOW EVER RECORDED IN AUGUST

DEGREE_DAYS
HEATING TOTAL       0                10     -10        0
 SINCE 7/1          0                16     -16        0
COOLING TOTAL     319               244      75      382
 SINCE 1/1       1122               688     434      863

FREEZE DATES
RECORD
 EARLIEST     09/08/1962
 LATEST       06/08/2007
EARLIEST                        10/07
LATEST                          05/05
..................................................

WIND (MPH)
AVERAGE WIND SPEED              9.9
RESULTANT WIND SPEED/DIRECTION   3/217
HIGHEST WIND SPEED/DIRECTION    38/330    DATE  08/30
HIGHEST GUST SPEED/DIRECTION    45/330    DATE  08/30

SKY COVER
POSSIBLE SUNSHINE (PERCENT)   MM
AVERAGE SKY COVER           0.50
NUMBER OF DAYS FAIR            8
NUMBER OF DAYS PC             22
NUMBER OF DAYS CLOUDY          1

AVERAGE RH (PERCENT)     34

WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM              4     MIXED PRECIP               0
HEAVY RAIN                0     RAIN                       0
LIGHT RAIN                9     FREEZING RAIN              0
LT FREEZING RAIN          0     HAIL                       0
HEAVY SNOW                0     SNOW                       0
LIGHT SNOW                0     SLEET                      0
FOG                       0     FOG W/VIS <= 1/4 MILE      0
HAZE                      4

-  INDICATES NEGATIVE NUMBERS.
R  INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T  INDICATES TRACE AMOUNT.