With the last part of December fresh in our minds, it would not be surprising to think of the month as a cold one. However, reaching back, if you recall, we actually enjoyed a lot of mild days earlier and very little precipitation. As a result, December 2017 goes into the books as a warm and dry one.
The first half of the month was notable for stable conditions yielding above normal temperatures and no precipitation. Denver set a record high temperature on the 12th of 69 degrees which was also our warmest reading of the month.
Not long after the warmth came the cold. Arctic air infiltrated from the north on the 21st resulting in much cooler temperatures and a pre-Christmas snow. This was followed by another snow on the 23rd that lasted into the early morning hours of Christmas Eve. Single digit lows were seen for seven days from the 21st to the 27th.
We then saw a brief warmup for the 27th to the 29th but that was short lived. We closed out the month with the final two days’ high temperatures failing to reach even the freezing mark.
On average, Denver’s temperature for December comes in at 30.0 degrees. Both Thornton and the Mile High City came in above that with average readings of 31.8 degrees and 33.2 degrees respectively.
Thornton saw its warmest temperature reading of 69.1 degrees on the 12th and its coldest of 1.6 degrees on the morning of the 27th. Denver’s warmest reading of 69 degrees also came on the 12th and its coldest of -4 degrees came on the 24th.
In terms of precipitation, Thornton saw a mere 0.16 inch of liquid in its bucket for the month. Denver was a bit better with 0.21 inches. Both were below the long-term Denver average of 0.35 inches.
December on average brings 8.5 inches of snowfall to Denver. Thornton fell well short of that with 4.7 inches and Denver just a bit less with 4.0 inches.
Click here to view Thornton’s December 2017 climate report.
CLIMATE REPORT
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
645 AM MST MON JAN 1 2018
...................................
...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF DECEMBER 2017...
CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2017
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 12/12 62 7 65 12/30
LOWEST -4 12/24 -4 0 -15 12/17
AVG. MAXIMUM 48.3 42.8 5.5 42.7
AVG. MINIMUM 18.0 17.1 0.9 12.9
MEAN 33.2 30.0 3.2 27.8
DAYS MAX >= 90 0 0.0 0.0 0
DAYS MAX <= 32 4 5.8 -1.8 6
DAYS MIN <= 32 28 29.4 -1.4 30
DAYS MIN <= 0 1 2.0 -1.0 4
PRECIPITATION (INCHES)
RECORD
MAXIMUM 5.21 1913
MINIMUM 0.00 1881
TOTALS 0.21 0.35 -0.14 0.78
DAILY AVG. 0.01 0.01 0.00 0.03
DAYS >= .01 4 4.1 -0.1 6
DAYS >= .10 1 1.1 -0.1 2
DAYS >= .50 0 0.1 -0.1 0
DAYS >= 1.00 0 0.0 0.0 0
GREATEST
24 HR. TOTAL 0.10 12/23 TO 12/23
STORM TOTAL 0.10 12/23 TO 12/23
SNOWFALL (INCHES)
RECORDS
TOTAL 57.4 1913
TOTALS 4.0 2017 8.5
DEGREE_DAYS
HEATING TOTAL 979 1086 -107 1146
SINCE 7/1 2150 2468 -318 2042
COOLING TOTAL 0 0 0 0
SINCE 1/1 881 769 112 878
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 10.0
RESULTANT WIND SPEED/DIRECTION 2/214
HIGHEST WIND SPEED/DIRECTION 37/270 DATE 12/04
HIGHEST GUST SPEED/DIRECTION 48/280 DATE 12/04
SKY COVER
POSSIBLE SUNSHINE (PERCENT) MM
AVERAGE SKY COVER 0.50
NUMBER OF DAYS FAIR 8
NUMBER OF DAYS PC 18
NUMBER OF DAYS CLOUDY 5
AVERAGE RH (PERCENT) 49
WEATHER CONDITIONS. NUMBER OF DAYS WITH
FOG OR MIST 12
FOG VSBY LESS 1/4 MI 4
THUNDER 0
ICE PELLETS 0
HAIL 0
FREEZING RAIN DRIZZLE 0
DUST STORM 0
SMOKE OR HAZE 5
BLOWING SNOW 0
TORNADO 0
- INDICATES NEGATIVE NUMBERS.
R INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T INDICATES TRACE AMOUNT.