Thornton’s September this year was relatively benign and lacking much drama although it was a bit of a rollercoaster. Temperatures had their large swings and we saw a couple of days with healthy precipitation.
The month started out slightly cooler than normal on the first but then warmed over the next couple of days to a high of 93.8 degrees on the third.
Low pressure and a cold front brought an end to the heat and three days of cooler than normal temperatures arrived. Two of those three days combined to deliver more than a half inch of precipitation.
Warmer and drier weather returned for a few days before a more potent cold front pushed in. The 11th and 12th of the month brought our coldest days of the month. Low temperatures became quite chilly dropping to below freezing on the morning of the 13th as the system moved out.
Some rain fell on those days and while Denver recorded a trace of snow on the morning of the 12th, none was seen in Thornton.
We then rebounded nicely with 10 of the next 11 days seeing high temperatures above 80 degrees, many of those in the mid to upper 80s.
Things cooled down for the last three days as a strong system moved through. We recorded a significant 0.86 inches of rain on the 29th.
Thornton’s overall average temperature for the month was 62.6 degrees. This was a bit below the long term Denver average of 63.4 degrees. Out at the airport, it was as usual warmer with an average of 64.8 degrees.
Temperatures ranged from a high of 93.8 degrees on the 3rd down to a chilly low of 30.9 degrees on the 13th. Denver’s warmest day matched ours on the 3rd with a reading of 94 degrees while the Mile High City’s coldest reading of 33 degrees came on the 12th.
Denver saw one temperature record during the month. The record high minimum for September 25th was set with a reading of 56 degrees. This tied the record for the date last set in 1981.
In terms of precipitation, Thornton recorded 1.89 inches in the rain bucket for the month. Denver saw 1.79 inches. Both were well above Denver’s September average of 0.96 inches.
A daily rainfall record for Denver was set on the 29th when 1.01 inches fell at the airport. The old record of 0.96 inch for the date was set in 1959.
Click here to view Thornton’s September 2014 climate report.
...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF SEPTEMBER 2014...
CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2014
WEATHER OBSERVED NORMAL DEPART LAST YEAR`S
VALUE DATE(S) VALUE FROM VALUE DATE(S)
NORMAL
................................................................
TEMPERATURE (F)
RECORD
HIGH 97 09/06/2013
09/05/2013
09/04/1995
LOW 17 09/29/1985
HIGHEST 94 09/03 91 3 97 09/06
09/05
LOWEST 33 09/12 35 -2 38 09/28
AVG. MAXIMUM 78.9 78.5 0.4 78.6
AVG. MINIMUM 50.6 48.3 2.3 54.2
MEAN 64.8 63.4 1.4 66.4
DAYS MAX >= 90 2 3.4 -1.4 7
DAYS MAX <= 32 0 0.0 0.0 0
DAYS MIN <= 32 0 0.8 -0.8 0
DAYS MIN <= 0 0 0.0 0.0 0
PRECIPITATION (INCHES)
RECORD
MAXIMUM 5.61 2013
MINIMUM T 1892 1944
TOTALS 1.79 0.96 0.83 5.61
DAILY AVG. 0.06 0.03 0.03 0.19
DAYS >= .01 9 6.5 2.5 10
DAYS >= .10 4 3.3 0.7 10
DAYS >= .50 1 0.6 0.4 3
DAYS >= 1.00 1 0.1 0.9 2
GREATEST
24 HR. TOTAL 1.01 09/29 TO 09/29 09/14 TO 09/15
SNOWFALL (INCHES)
RECORDS
TOTAL 17.2 1991
TOTALS T 1.3 -1.3 0
DEGREE_DAYS
HEATING TOTAL 91 125 -34 83
SINCE 7/1 98 141 -43 83
COOLING TOTAL 88 76 12 133
SINCE 1/1 701 764 -63 999
FREEZE DATES
RECORD
EARLIEST 09/08/1962
LATEST 06/08/2007
EARLIEST 10/07
LATEST 05/05
.....................................................
WIND (MPH)
AVERAGE WIND SPEED 9.4
RESULTANT WIND SPEED/DIRECTION 3/186
HIGHEST WIND SPEED/DIRECTION 33/350 DATE 09/09
HIGHEST GUST SPEED/DIRECTION 40/360 DATE 09/09
SKY COVER
POSSIBLE SUNSHINE (PERCENT) MM
AVERAGE SKY COVER 0.50
NUMBER OF DAYS FAIR 13
NUMBER OF DAYS PC 11
NUMBER OF DAYS CLOUDY 6
AVERAGE RH (PERCENT) 55
WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM 3 MIXED PRECIP 0
HEAVY RAIN 1 RAIN 6
LIGHT RAIN 9 FREEZING RAIN 0
LT FREEZING RAIN 0 HAIL 0
HEAVY SNOW 0 SNOW 0
LIGHT SNOW 2 SLEET 0
FOG 9 FOG W/VIS <= 1/4 MILE 1
HAZE 3
- INDICATES NEGATIVE NUMBERS.
R INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T INDICATES TRACE AMOUNT.
Late afternoon thunderstorms and showers began falling yesterday and continued through midnight. Areas to the east and north, including Denver International Airport, saw more precipitation than other locations and DIA set a daily rainfall record as a result.
The big chill continued on Thursday as for the second day in a row the Mile High City’s high temperature set a record as the coldest for the date.
With a large, cold air mass settled in across much of the nation’s midsection, weather records are bound to fall. In the Mile High City the record for coldest high temperature for the date was not just broken but smashed.
Thanks to a snowy start and a similarly snowy finish, the month of January 2014 climbed onto the list of top 10 January snow measurements in the Mile High City.
Colorado’s famously inconsistent weather appears to be on full display this month. Just two weeks ago we were setting records for cold. Today we broke a record high temperature and tied the record high minimum.