IF THIS SUMMER DID NOT FEEL AS HOT AS PAST SUMMERS -- THERE IS GOOD REASON FOR THIS.  DURING THE WARM SEASON OF 2008, MUCH OF SOUTH DAKOTA AND WEST CENTRAL MINNESOTA DID NOT EXPERIENCE THE USUAL NUMBER OF DAYS WHEN HIGH TEMPERATURES REACHED OR EXCEEDED 90F, 95F, OR 100F.  

ONE OF THE MORE INTERESTING FACTS IS THAT PIERRE DID NOT RECORD A HIGH TEMPERATURE OF 100 DEGREES THIS SUMMER.  IN AN AVERAGE YEAR (BASED ON THE 30 YEAR NORMALS), PIERRE WOULD EXPERIENCE ABOUT 9 DAYS WHEN THE TEMPEATURE WOULD EXCEED 100F.  DATING BACK TO 1933 THERE HAS ONLY BEEN ONE OTHER YEAR (1993) WHEN A HIGH TEMPERATURE FAILED TO REACH 100 DEGREES DURING THE WARM SEASON.  PIERRE DID GET CLOSE TO 100 F ON SEVERAL OCCASSIONS - MOST NOTABLY ON AUGUST 30TH WHEN THE MERCURY ROSE TO 99 F.  HOWEVER, THE NUMBER OF DAYS WHEN HIGH TEMPERATURES EXCEEDED 90F OR 95F AT PIERRE, ABERDEEN, AND WATERTOWN WAS ALSO WELL BELOW CLIMATOLOGICAL AVERAGES (SEE TABLES BELOW).  

CLIMATOLOGICALLY SPEAKING, IT IS HIGHLY UNLIKELY THAT PIERRE WILL RECORD A TEMPERATURE OF 100F THROUGH THE REMAINDER OF 2008.  THE LATEST A 100 DEGREE TEMPEATURE WAS EVER RECORDED AT PIERRE WAS SEPTEMBER 26TH, 1974.  

THE CAUSE OF SIGNIFICANT TEMPERATURE DEPARTURES CAN RANGE FROM CHANGES IN THE GLOBAL SCALE CIRCULATION (I.E. EL NINO/LA NINA) TO MORE LOCAL EFFECTS (I.E. DISTRIBUTION OF RAINFALL). WHILE IT IS DIFFICULT TO PIN DOWN ONE UNDERLYING REASON FOR THE BELOW NORMAL HIGH TEMPERATURES THIS SUMMER, THERE IS STRONG EVIDENCE TO BELIEVE THAT THEY CAN BE AT LEAST PARTIALLY ATTRIBUTED TO THE ABOVE NORMAL PRECIPITATION THAT HAS FELL OVER PORTIONS OF THE AREA EARLIER THIS SUMMER. THE ABOVE NORMAL PRECIPITATION LED TO INCREASED VEGETATION AND HIGHER SOIL MOISTURE SUCH THAT INCOMING SOLAR RADIATION WAS USED FOR EVAPORATION RATHER THAN HEATING.  IN PAST YEARS...MUCH OF CENTRAL AND WESTERN SOUTH DAKOTA EXPERIENCED DROUGHT CONDITIONS WHEREAS THE DRIER AIR WAS ABLE TO HEAT MORE EFFICIENTLY.

LISTED BELOW IS A SUMMARY OF SEVERAL INTERESTING HEAT RELATED FACTS FOR ABERDEEN...PIERRE...AND WATERTOWN.

WATERTOWN (1893-2008)

AVG NUMBER OF DAYS WITH TEMPERATURES AT OR ABOVE 100F:  1.2

2008.....0
2007.....1
2006.....4
2005.....0
2004.....0

AVG NUMBER OF DAYS WITH TEMPERATURES AT OR ABOVE 95F:  5.5
2008.....0
2007.....3
2006.....7
2005.....4
2004.....0

AVG NUMBER OF DAYS WITH TEMPERATURES AT OR ABOVE 90F: 16.8
2008.....4
2007.....13
2006.....17
2005.....14
2004.....2

RECORD HOTTEST TEMPERATURE:                       110 F (7/20/1934)
YEAR WITH THE MOST 100F TEMPERATURES:    1933 - 17 DAYS
YEAR WITH THE MOST 95F TEMPERATURES:     1936, 1933 - 34 DAYS
YEAR WITH THE MOST 90F TEMPERATURES:     1933 - 53 DAYS
EARLIEST 90F TEMPERATURE:                             4/2/1910
LATEST 90F TEMPERATURE:                                10/5/1963
EARLIEST 100F TEMPERATURE:                           5/28/1934
LATEST 100F TEMPERATURE:                               9/10/1931

Mike Fowle - Science and Operations Officer