Historically July is a pretty busy month in terms of weather as thunderstorms are very common. July 2011 lived up to the month’s reputation as the middle of the month saw a seemingly endless stream of heavy, wet thunderstorms. This was followed by a string of 90 degree and warmer days that approached record setting territory.
The big story for the month was the precipitation as there was a lot of it. DIA saw sixteen thunderstorms during July, five more than normal. The official Denver monitoring at the airport recorded 3.41 inches of rain which was well above the normal of 2.16 inches. The measurement fell just shy of making the list of top 10 wettest July’s on record.
The station at DIA however lived up to its reputation as under-reporting rainfall as compared to locations closer to downtown. In fact, a station the old Stapleton site recorded 6.54 inches. Here in Thornton 5.51 inches fell into our rain bucket.
- What is up with the weather records at DIA? Click here for more about how the station at the airport is causing problems with Denver’s climate records.
One precipitation record was set during the month when 1.03 inches of rain fell on the 13th. This easily bested the previous 24 hour record for the date of 0.45 inch set in 1993.
Temperatures for the month were considerably above normal but fell short of ‘top 10’ status. The average temperature for the month, as recorded at DIA, was 75.9 degrees. This was 2.5 degrees above the normal of 73.4.
The warmest temperature of the month occurred on the Fourth of July when the mercury climbed to 99 degrees. On the opposite end, 56 degrees on the 1st of the month was the coldest reading.
In all, 20 days saw temperatures at or above 90 degrees during July 2011; five more than normal. July 15th started a string of 18 consecutive days of 90 degree or warmer high temperatures. That streak will go into the books as tying for the second longest in history.
Thornton, like most other places in the metro area, was not near as warm. Our average temperature was 73.8 degrees, right near normal. Our warmest temperature occurred on the 4th as well and matched Denver’s mark of 99 degrees. The mercury dipped to 53.6 degrees on the 1st and was our coldest temperature.
Click here to view Thornton’s July 2011 climate summary
...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF JULY 2011...
CLIMATE NORMAL PERIOD 1971 TO 2000
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 07/20/2005
LOW 42 07/04/1903
07/31/1873
HIGHEST 99 07/31 105 -6 102 07/17
07/04
LOWEST 56 07/01 42 14 53 07/09
07/05
07/04
AVG. MAXIMUM 91.1 88.0 3.1 89.3
AVG. MINIMUM 60.7 58.7 2.0 59.5
MEAN 75.9 73.4 2.5 74.4
DAYS MAX >= 90 20 15.0 5.0 18
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 6.41 1965
MINIMUM 0.01 1901
TOTALS 3.41 2.16 1.25 3.70
DAILY AVG. 0.11 0.07 0.04 0.12
DAYS >= .01 11 9.3 1.7 13
DAYS >= .10 7 MM MM 5
DAYS >= .50 2 MM MM 2
DAYS >= 1.00 2 MM MM 2
GREATEST
24 HR. TOTAL 1.08 07/12 TO 07/13 1.84 07/04/10 TO 07/04/10
SNOWFALL (INCHES)
RECORDS
TOTAL 0.0 NONE EVER RECORDED IN JULY
TOTALS 0.0 0.0
DEGREE_DAYS
HEATING TOTAL 0 1 -1 3
SINCE 7/1 0 1 -1 3
COOLING TOTAL 346 261 85 303
SINCE 1/1 481 422 59 482
FREEZE DATES
RECORD
EARLIEST 09/08/1962
LATEST 06/08/2007
EARLIEST 10/07
LATEST 05/05
......................................................
WIND (MPH)
AVERAGE WIND SPEED 9.5 9.1
RESULTANT WIND SPEED/DIRECTION 3/181 MM
HIGHEST WIND SPEED/DIRECTION 51/210 DATE 07/13 41 07/30/10
HIGHEST GUST SPEED/DIRECTION 68/300 DATE 07/14 48 07/30/10
SKY COVER
POSSIBLE SUNSHINE (PERCENT) MM
AVERAGE SKY COVER 0.50
NUMBER OF DAYS FAIR 6
NUMBER OF DAYS PC 22
NUMBER OF DAYS CLOUDY 3
AVERAGE RH (PERCENT) 50
WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM 0 MIXED PRECIP 0
HEAVY RAIN 4 RAIN 6
LIGHT RAIN 17 FREEZING RAIN 0
LT FREEZING RAIN 0 HAIL 4
HEAVY SNOW 0 SNOW 0
LIGHT SNOW 0 SLEET 0
FOG 5 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.
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.
