You didn’t need to know the statistics to be well aware that August was unusually warm and dry in Thornton and Denver. The month saw little precipitation and record setting temperatures became commonplace, particularly in the latter half of the month.
For moisture, Denver recorded a mere 0.30 inch in the rain bucket at Denver International Airport. This was 1.27 inches below the normal of 1.57 inches. The month barely missed making the list of top 10 driest Augusts by only 0.02 inch.
Afternoon thunderstorms were seen 12 times at DIA but only one brought measurable precipitation. The storms were typically high-based and yielded little more than wind.
Thornton followed DIA’s lead with little precipitation as we only saw 0.27 inch during the month.
Temperatures were the real weather story for August 2011 as rather than seeing cooler temperatures through the month like normal, the mercury stayed exceedingly high.
Overall DIA saw an average temperature of 77.0 degrees making it the hottest August on record. This surpassed the previous record August from 1937 when 76.8 degrees was seen. The month also went into the record books as the sixth warmest month ever recorded in Denver.
Temperatures ranged from a high of 99 degrees on the 25th down to a low of 55 degrees on the 20th. Through August 31st, Denver had seen 71 consecutive days of 80 degrees or warmer weather. This easily bested the previous longest streak of 59 days set in 2002.
Seven individual temperature records were set during the month. These included a tied record high on the 18th of 98 degrees last set in 1986; the 23rd tied the record high of 98; the 24th set a new record high for the date of 98 degrees; the 25th set a new record high of 99 degrees; the 28th set a record high of 96 degrees; the 28th saw a record high minimum of 67 degrees; the 31st tied the record high of 98 degrees.
Here in Thornton we were certainly hot but not nearly as much so as DIA. We recorded an average temperature of 74 degrees. Our warmest reading was 96.2 degrees and our coolest was 54. In all we saw 20 days with temperatures of 90 degrees or warmer.
While the high temperatures were notable, DIA benefits from later arrival of the typical afternoon thunderstorms due to its location further east of the rest of Denver. This certainly aided in the airport recording higher temperatures than anywhere else in the metro area. For more on that story, check out the Denver Weather Examiner.
Below are the official Denver weather statistics for August 2011. Click here to view Thornton’s August 2011 climate summary.
CLIMATE REPORT...CORRECTED
NATIONAL WEATHER SERVICE BOULDER, CO
430 PM MDT FRI SEP 2 2011
...................................
...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF AUGUST 2011...
CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2011
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 99 08/25 105 -6 97 08/22
LOWEST 55 08/20 40 15 47 08/17
AVG. MAXIMUM 92.7 87.2 5.5 88.6
AVG. MINIMUM 61.3 57.9 3.4 59.0
MEAN 77.0 72.5 4.5 73.8
DAYS MAX >= 90 22 11.5 10.5 12
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 0.30 1.57 -1.27 1.05 DAILY AVG. 0.01 0.05 -0.04 0.03 DAYS >= .01 3 8.6 -5.6 6 DAYS >= .10 1 4.3 -3.3 3 DAYS >= .50 0 1.2 -1.2 1 DAYS >= 1.00 0 0.3 -0.3 0 GREATEST 24 HR. TOTAL 0.27 08/03 TO 08/03 0.68 08/01/10 TO 08/01/10
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 5 -5 0
SINCE 7/1 0 11 -11 3
COOLING TOTAL 382 244 138 280
SINCE 1/1 863 688 175 762
FREEZE DATES
RECORD
EARLIEST 09/08/1962
LATEST 06/08/2007
EARLIEST 10/07
LATEST 05/05
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WIND (MPH)
AVERAGE WIND SPEED 8.8
RESULTANT WIND SPEED/DIRECTION 3/202
HIGHEST WIND SPEED/DIRECTION 39/180 DATE 08/31 38/190 08/12
HIGHEST GUST SPEED/DIRECTION 48/200 DATE 08/31 45/340 08/12
08/16
SKY COVER
POSSIBLE SUNSHINE (PERCENT) MM (NO LONGER RECORDED)
AVERAGE SKY COVER 0.50
NUMBER OF DAYS FAIR 4
NUMBER OF DAYS PC 26
NUMBER OF DAYS CLOUDY 1
AVERAGE RH (PERCENT) 41
WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM 0 MIXED PRECIP 0
HEAVY RAIN 1 RAIN 1
LIGHT RAIN 8 FREEZING RAIN 0
LT FREEZING RAIN 0 HAIL 0
HEAVY SNOW 0 SNOW 0
LIGHT SNOW 0 SLEET 0
FOG 4 FOG W/VIS <= 1/4 MILE 1
HAZE 5
- INDICATES NEGATIVE NUMBERS.
R INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T INDICATES TRACE AMOUNT.
As temperatures start to drop, September reminds us that summer is at an end and fall is now here. Sunshine is predominant though as the month actually has the highest percentage of sun out of any month. Sunny days and clear, cool nights are the standard weather pattern for the month.
Thornton’s June 2011 weather was a relatively typical one with average temperatures but also with above normal precipitation. The month also signifies the official end of the 2010 to 2011 snow season which was absolutely dismal.
June is historically Denver’s severe weather month and severe thunderstorms, tornadoes and hail are notorious visitors to Denver and across eastern Colorado during the month.