The first quarter of the year started out dry but April started to signal a turn toward wetter conditions and the month of May certainly followed through on that. Not only was it a very wet month, it was also much cooler than normal.
A seemingly endless series of disturbances moved through the state almost from the first day through the last day of May 2015. We started out dry but the third of the month began the wet period with five straight days of precipitation. That was capped off by a decent shot of snowfall on the 10th of the month.
After that we did dry out for at least a few days before the wet weather returned on the 15th, albeit with lesser amounts of precipitation overall. By the time the month was over, 18 of the 31 days had seen measureable precipitation in Thornton.
Temperatures were quite cool for the month with the average in Thornton coming in at 52.2 degrees. This was nearly five degrees below Denver’s May average of 57.1 degrees. As measured at Denver International Airport, the Mile High City officially saw an overage of 53.0 degrees.
Thornton’s mercury readings ranged from a high of 87.3 degrees on the 31st down to a low of 27.8 degrees on the morning of the 10th. Denver saw its warmest reading of 85 degrees on the 31st also and its coldest reading of 27 degrees occurred on the 9th and 10th.
In terms of precipitation, the numbers help to showcase just how wet of a month it was. Here in Thornton we recorded 6.40 inches of liquid precipitation, far above the long term Denver average for May of 2.12 inches. Officially, Denver also saw above normal precipitation although not by near as much as they recorded 3.76 inches.
That reading was not enough to push May 2015 into the books as one of the top 10 wettest Mays. However, the airport’s outlying location as compared to historical measurement sites is probably the only reason why. As Thornton’s measurement and those of other station’s shows, we were far wetter than what DIA saw.
Snowfall in May is not unusual and Thornton saw 5.1 inches from one storm on the 9th and 10th. Out at the airport 4.0 inches was recorded. Both were a good bit above the May average of 1.1 inches.
Click here to view Thornton’s May 2015 climate report.
CLIMATE REPORT
NATIONAL WEATHER SERVICE BOULDER, CO
645 AM MDT MON JUN 1 2015
...................................
...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF MAY 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 95 05/26/1942
LOW 19 05/02/2013
05/03/1907
HIGHEST 85 05/31 87 05/28
05/29
LOWEST 27 05/10 30 05/12
05/09
AVG. MAXIMUM 63.3 71.5 -8.2 70.6
AVG. MINIMUM 42.7 42.7 0.0 44.5
MEAN 53.0 57.1 -4.1 57.5
DAYS MAX >= 90 0 0.8 -0.8 0
DAYS MAX <= 32 0 0.0 0.0 0
DAYS MIN <= 32 3 1.9 1.1 4
DAYS MIN <= 0 0 0.0 0.0 0
PRECIPITATION (INCHES)
RECORD
MAXIMUM 8.57 1876
MINIMUM 0.06 1974
TOTALS 3.76 2.12 1.64 3.51
DAILY AVG. 0.12 0.07 0.05 0.11
DAYS >= .01 19 9.4 9.6 13
DAYS >= .10 10 4.8 5.2 6
DAYS >= .50 2 1.2 0.8 3
DAYS >= 1.00 1 0.2 0.8 1
GREATEST
24 HR. TOTAL 1.18 05/08 TO 05/09 05/20 TO 05/21
SNOWFALL (INCHES)
TOTAL 4.0 1.1
RECORD MAY 15.5 1898
DEGREE_DAYS
HEATING TOTAL 367 265 102 244
SINCE 7/1 5572 5996 -424 5974
COOLING TOTAL 4 21 -17 21
SINCE 1/1 4 22 -18 21
FREEZE DATES
RECORD
EARLIEST 09/08/1962
LATEST 06/08/2007
NORMAL
EARLIEST 10/07
LATEST 05/05
..................................................
WIND (MPH)
AVERAGE WIND SPEED 9.3
RESULTANT WIND SPEED/DIRECTION 2/106
HIGHEST WIND SPEED/DIRECTION 45/280 DATE 05/02
HIGHEST GUST SPEED/DIRECTION 54/280 DATE 05/02
SKY COVER
POSSIBLE SUNSHINE (PERCENT) MM
AVERAGE SKY COVER 0.80
NUMBER OF DAYS FAIR 0
NUMBER OF DAYS PC 15
NUMBER OF DAYS CLOUDY 16
AVERAGE RH (PERCENT) 70
WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM 0 MIXED PRECIP 0
HEAVY RAIN 2 RAIN 9
LIGHT RAIN 23 FREEZING RAIN 0
LT FREEZING RAIN 0 HAIL 0
HEAVY SNOW 1 SNOW 1
LIGHT SNOW 2 SLEET 0
FOG 14 FOG W/VIS <= 1/4 MILE 7
HAZE 3
- INDICATES NEGATIVE NUMBERS.
R INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T INDICATES TRACE AMOUNT.