Warm and dry were the key weather words for the start of December 2015. That however changed as the month progressed and colder, wetter weather arrived.
High pressure dominated the start of the month leading to 10 out of the first 11 days of the month seeing above normal temperatures. No precipitation was recorded over that period as well.
Things began to change on the 12th of the month as Thornton saw a couple of inches of snowfall and temperatures dropped. A second, far more potent storm arrived on the 15th giving the Mile High City its heaviest snowfall of the season to that point.
Warmer and drier conditions returned up until Christmas. For the holiday, temperatures were over 15 degrees below normal and the afternoon and evening brought a white Christmas with moderate snowfall.
We then wrapped up the month with a string of well below average temperatures. In fact, the mercury remained below the freezing mark for the balance of the month.
Thornton’s average temperature for the month came in at 29.3 degrees. That is just below the long term Denver average of 30.0 degrees. Out at the airport where Denver’s official measurements are made, the average was virtually identical to Thornton’s at 29.4 degrees.
Highs in Thornton ranged from a 66.5 degrees maximum on the 9th down to a low of 00.3 degrees on the morning of the 28th. Denver saw its warmest temperature on the 9th also with a high of 69 degrees. Its low came in at 0 degrees on the 17th and 28th.
In terms of precipitation, Thornton recorded 0.79 inches in the bucket. At DIA, Denver was just a bit drier at 0.71 inches. The December average for Denver is 0.35 inches.
Denver averages 8.7 inches of snowfall during December. Both Thornton and Denver bested the average with 14.2 inches and 11.3 inches respectively.
Click here to view Thornton’s December 2015 climate report.
From the National Weather Service:
CLIMATE REPORT
NATIONAL WEATHER SERVICE BOULDER, CO
130 PM MST FRI JAN 1 2016
...................................
...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF DECEMBER 2015...
CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2015
WEATHER OBSERVED NORMAL DEPART LAST YEAR`S
VALUE DATE(S) VALUE FROM VALUE DATE(S)
NORMAL
................................................................
TEMPERATURE (F)
RECORD
HIGH 79 12/05/1939
LOW -25 12/22/1990
12/24/1876
HIGHEST 69 12/09 62 7 66 12/12
LOWEST 0 12/28 -4 4 -19 12/30
12/17
AVG. MAXIMUM 40.9 42.8 -1.9 44.1
AVG. MINIMUM 17.9 17.1 0.8 18.5
MEAN 29.4 30.0 -0.6 31.3
DAYS MAX >= 90 0 0.0 0.0 0
DAYS MAX <= 32 10 5.8 4.2 5
DAYS MIN <= 32 28 29.4 -1.4 31
DAYS MIN <= 0 2 2.0 0.0 2
PRECIPITATION (INCHES)
RECORD
MAXIMUM 5.21 1913
MINIMUM 0.00 1881
TOTALS 0.71 0.35 0.36 0.59
DAILY AVG. 0.02 0.01 0.01 0.02
DAYS >= .01 5 4.1 0.9 7
DAYS >= .10 3 1.1 1.9 2
DAYS >= .50 0 0.1 -0.1 0
DAYS >= 1.00 0 0.0 0.0 0
GREATEST
24 HR. TOTAL 0.32 12/15 TO 12/15
SNOWFALL (INCHES)
RECORDS
TOTAL 11.3 8.7
RECORD DECEMBER 57.4 1913
DEGREE_DAYS
HEATING TOTAL 1097 1086 11 1037
SINCE 7/1 2187 2468 -281 2291
COOLING TOTAL 0 0 0 0
SINCE 1/1 877 769 108 701
FREEZE DATES
RECORD
EARLIEST 09/08/1962
LATEST 06/08/2007
EARLIEST 10/07
LATEST 05/05
.................................................
WIND (MPH)
AVERAGE WIND SPEED 9.8
RESULTANT WIND SPEED/DIRECTION 4/210
HIGHEST WIND SPEED/DIRECTION 41/280 DATE 12/09
HIGHEST GUST SPEED/DIRECTION 64/290 DATE 12/15
SKY COVER
POSSIBLE SUNSHINE (PERCENT) MM
AVERAGE SKY COVER 0.50
NUMBER OF DAYS FAIR 5
NUMBER OF DAYS PC 22
NUMBER OF DAYS CLOUDY 4
AVERAGE RH (PERCENT) 58
WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM 0 MIXED PRECIP 0
HEAVY RAIN 0 RAIN 0
LIGHT RAIN 0 FREEZING RAIN 0
LT FREEZING RAIN 0 HAIL 0
HEAVY SNOW 1 SNOW 3
LIGHT SNOW 8 SLEET 0
FOG 12 FOG W/VIS <= 1/4 MILE 3
HAZE 6
- INDICATES NEGATIVE NUMBERS.
R INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T INDICATES TRACE AMOUNT.
Our most significant winter weather storm is set to impact Thornton and the Colorado Front Range. A Blizzard Warning has been issued and we expect to see significant snowfall and a wide array of impacts.
