Sweltering, unseasonably warm temperatures gripped much of the contiguous United States last month breaking many records. In the final analysis of the month, NOAA announced that July was the hottest month ever recorded in the U.S. How hot was it? Read the rest of this story on Examiner.com
The National Oceanic and Atmospheric Administration (NOAA) released its climate summary for June 2012 showing the United States experienced an unusually warm month. Most notably the U.S. has recorded its warmest first half of the year on record and the warmest 12 month period on record. Climate change? Learn more about the warm weather across the nation on Examiner.com.
As officially measured at Denver International Airport, the Mile High City hit a high temperature of 94° at 2:25pm. This broke the old record high temperature for the date of 93° set in 2010, 1990 and 1977.
The problem? No other reliable station in the metro area came anywhere near that high of a temperature reading.
For comparison, Rocky Mountain Regional Airport saw 91°, Centennial 88°, Boulder 91°, Denver City Park 90°, Stapleton 90° and here in Thornton we recorded 91°.
Once again we see how the move of Denver’s official monitoring station to DIA are altering our climate records. For more details on this controversial topic: The fallacy of Denver’s climate records: Weather station move skews data
As with any month in the Denver area, December can bring a variety of conditions. Certainly we have seen bitter cold and heavy snow but in other years dry and mild conditions prevailed.
Based on the updated 1981 to 2010 averages from the National Weather Service, the month is actually our coldest of the year. It also is our third snowiest behind March and November.
Winter weather is typically what we think of when we think about December and it is indeed prone to winter extremes.
In fact, our coldest month in Denver history was in December 1983. In terms of snow, our snowiest month ever occurred in December 1913. More recently the Christmas Eve Blizzard of 1982 and the storms on December 2006 invoke snow-filled memories.
Remember, when the snow starts flying, stay up to date with ThorntonWeather.com: ‘Like’ us on Facebook, follow us on Twitter and add us to your Google+ circles
October 2011 started out quite warm but then stabilized into a seasonal pattern. As is often the case with Colorado weather though, at one point we went from record high temperatures to snow in a span of two days.
In terms of temperature, Denver finished the month with an overall overage temperature of 52.6 degrees. This was 1.6 degrees above the normal for the month of 50.9 degrees. Temperatures ranged from a high of 87 degrees on the first of the month down to 14 degrees on the 26th and 27th.
Here in Thornton we were slightly cooler with an average temperature of 50.4 degrees. Our highs ranged from a top mark of 86.6 degrees on the first down to a very cold 12.8 degrees on the 27th.
Two record high temperatures were tied or broken during the month. On the 15th, the mercury climbed to 82 degrees which tied the record for the date last set in 1938. On the 24th the temperature hit 80 degrees, breaking the previous record high for the date of 79.
Quite a bit more precipitation was recorded than normal during October 2011. 1.79 inches fell into the rain bucket at DIA which is 0.82 inch above normal. Much of that precipitation fell on October 8th when 1.04 inches was recorded, a record for the date. DIA also recorded a trace of snowfall, the first of the season.
The Mile High City was hit with its first snowstorm on the 25th and 26th when 8.5 inches of the white stuff fell. That also was the snowfall total for the month which far exceeded the normal of 4.2 inches.
Thornton nearly mirrored Denver’s precipitation as we recorded 1.75 inches during the month between rain and snowmelt. Our snowfall fell short of DIAs however as we recorded 6.6 inches during the storm late in the month.
Click here to view Thornton’s climate summary for October 2011.
From the National Weather Service:
...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF OCTOBER 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 90 10/01/1892
LOW -2 10/29/1917
HIGHEST 87 10/01 90 -3 85 10/03
LOWEST 14 10/26 -2 16 20 10/28
10/27
AVG. MAXIMUM 67.3 65.3 2.0 69.7
AVG. MINIMUM 37.9 36.6 1.3 40.9
MEAN 52.6 50.9 1.7 55.3
DAYS MAX >= 90 0 0.0 0.0 0
DAYS MAX = .01 4 5.3 -1.3 4
DAYS >= .10 3 2.4 0.6 2
DAYS >= .50 1 0.5 0.5 0
DAYS >= 1.00 1 0.1 0.9 0
GREATEST
24 HR. TOTAL 1.04 10/08 TO 10/08
SNOWFALL (INCHES)
RECORDS
TOTAL 31.2 1969
TOTALS 8.5 4.2
DEGREE_DAYS
HEATING TOTAL 400 438 -38 300
SINCE 7/1 495 576 -81 335
COOLING TOTAL 23 5 18 8
SINCE 1/1 964 769 195 870
FREEZE DATES
RECORD
EARLIEST 09/08/1962
LATEST 06/08/2007
EARLIEST 10/17 10/07
LATEST 05/05
...................................................
WIND (MPH)
AVERAGE WIND SPEED 9.8
RESULTANT WIND SPEED/DIRECTION 4/205
HIGHEST WIND SPEED/DIRECTION 49/210 DATE 10/06
HIGHEST GUST SPEED/DIRECTION 63/200 DATE 10/06
SKY COVER
POSSIBLE SUNSHINE (PERCENT) MM
AVERAGE SKY COVER 0.40
NUMBER OF DAYS FAIR 13
NUMBER OF DAYS PC 15
NUMBER OF DAYS CLOUDY 3
AVERAGE RH (PERCENT) 44
WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM 1 MIXED PRECIP 0
HEAVY RAIN 0 RAIN 1
LIGHT RAIN 5 FREEZING RAIN 0
LT FREEZING RAIN 0 HAIL 0
HEAVY SNOW 1 SNOW 2
LIGHT SNOW 3 SLEET 0
FOG 5 FOG W/VIS
Typically November is a quiet weather month with plenty of nice, fall days but it can also turn wet with plenty of snow and moisture. Just like Forest Gump’s proverbial box of chocolates, you never quite know what you are going to get.
Looking into the weather history books, we see that November is actually Denver’s second snowiest month, second only to March (April is third). Historically we average 10.7 inches of snow during the month.
One little known fact… November is the area’s least sunny month, tying with May with only 64 percent sunshine. September is the sunniest month with sunshine 74 percent of the time.
Get all the details on Denver’s November weather including a look back through history, a recap of last year and the statistics in our November weather preview.
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
..................................................
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 August 2011 came to a close and the numbers were crunched, they revealed what we already knew – it was one hot month! In fact, in the final tally Denver tied or set 10 different records during the month.
From the National Weather Service, here is the list of records:
Denver’s record setting August 2011 – From the National Weather Service:
How did Thornton compare?
Here in Thornton we were a bit cooler than what Denver’s official measurements at DIA recorded. This is in large part due to our location further to the west.
When the typical afternoon cloud cover and thunderstorms develop in the summer, it can take more than an hour for those conditions to reach DIA. As a result the station gets the benefit of a longer period of daytime heating. This works in Thornton’s favor as we stay a bit cooler.
For us, our overall average temperature for the month was 74.0 degrees – a full three degrees cooler than DIA. That doesn’t mean it wasn’t hot for us as we recorded 20 days with 90 degree or hotter weather and every day saw 80 degrees or higher.
Are the Denver weather records really valid? Check out the stories from Examiner.com below for why they may not be.
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.
Normal highs on the first of the month are 82 degrees with a low of 53. By the end of the month we see those high temperatures drop to an average of 73 and the lows get to a chilly 42. Overall the month averages 63.4 degrees.
Generally we can see just about any weather condition from thunderstorms to temperatures into the 90s to snow. Learn more in our complete September 2011 weather preview here.
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.
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.