For the second month in a row, Thornton saw temperatures well above normal and precipitation well below average. While the first half of 2019 started out cool and wet, the second appears to be headed the opposite direction.
High pressure was the dominating feature for the month. This served to keep precipitation away and colder air to our north.
The result was clear and served to make September 2019 one of the warmest Septembers on record. In fact, it was Denver’s second warmest September on record. Thornton wasn’t as warm but here too, it was our second warmest September since Thornton Weather launched 13 years ago.
Overall, Thornton saw an average temperature for the month of 67.0 degrees. This was well above Denver’s long term average temperature for September of 63.4 degrees. Out at DIA where the Mile High City’s official measurements are taken, it was even warmer with an average of 69.3 degrees for the month.
Temperatures in Thornton ranged from a high of 101 degrees on the 1st and 2nd down to a low of 41.7 degrees on the morning of the 26th. Denver’s maximum temperature for the month of 100 degrees came on the 2nd and its coldest of 40 degrees on the 22nd.
Denver’s 100 degree reading on the 2nd was not only a record high for the date, but it also was the latest in the year a 100 degree reading has ever been recorded. The old record was August 16th in 2002. Record high temperatures of 98 degrees were also recorded on the 1st and 5th.
In terms of precipitation, Denver averages 0.96 inches during September. Thornton and Denver recorded identical totals in September 2019 of 0.41 inches, less than half of the average.
Click here to view Thornton’s September 2019 climate report.
CLIMATE REPORT
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
826 AM MDT TUE OCT 1 2019
...................................
...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF SEPTEMBER 2019...
CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2019
WEATHER OBSERVED NORMAL DEPART LAST YEAR`S
VALUE DATE(S) VALUE FROM VALUE DATE(S)
NORMAL
................................................................
TEMPERATURE (F)
RECORD
HIGH 100 09/02/2019
LOW 17 09/29/1985
HIGHEST 100R 09/02 91 9 96 09/13
LOWEST 40 09/22 35 5 36 09/29
09/25
AVG. MAXIMUM 85.5 78.5 7.0 82.7
AVG. MINIMUM 53.2 48.3 4.9 52.8
MEAN 69.3 63.4 5.9 67.8
DAYS MAX >= 90 5 3.4 1.6 9
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 0.41 0.96 -0.55 0.18
DAILY AVG. 0.01 0.03 -0.02 0.01
DAYS >= .01 3 6.5 -3.5 5
DAYS >= .10 2 3.3 -1.3 0
DAYS >= .50 0 0.6 -0.6 0
DAYS >= 1.00 0 0.1 -0.1 0
GREATEST
24 HR. TOTAL 0.26 09/08 TO 09/08
SNOWFALL (INCHES)
RECORD SEPTEMBER 17.2 1971
TOTAL 0.0 1.3
DEGREE_DAYS
HEATING TOTAL 22 125 -103 69
SINCE 7/1 22 141 -119 78
COOLING TOTAL 158 76 82 160
SINCE 1/1 915 764 151 1022
FREEZE DATES
RECORD
EARLIEST 09/08/1962
LATEST 06/08/2007
EARLIEST 10/07
LATEST 05/05
.................................................................
WIND (MPH)
AVERAGE WIND SPEED 10.3
RESULTANT WIND SPEED/DIRECTION 3/165
HIGHEST WIND SPEED/DIRECTION 43/260 DATE 09/08
HIGHEST GUST SPEED/DIRECTION 56/260 DATE 09/08
SKY COVER
POSSIBLE SUNSHINE (PERCENT) MM
AVERAGE SKY COVER 0.40
NUMBER OF DAYS FAIR 14
NUMBER OF DAYS PC 15
NUMBER OF DAYS CLOUDY 1
AVERAGE RH (PERCENT) 45
- INDICATES NEGATIVE NUMBERS.
R INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T INDICATES TRACE AMOUNT.