2010...Much Wetter than Normal

The weather for 2010 across central and northeast South Dakota as well as west central Minnesota was much wetter than normal, especially across northeast South Dakota and west central Minnesota. The yearly average temperatures for 2010 were generally below normal and within a degree of normal.  Watertown was the only location with a yearly average temperature above normal and was due mainly to the warm minimum average temperatures.  Interestingly enough, both Aberdeen and Kennebec finished the year with an average temperature right at normal.  Bitter cold air in early January brought some record lows for the region with lows in the mid 20s to the mid 30s below zero. The heat was finally turned up in central and north central South Dakota in the Summer of 2010 where all locations warmed up to well over 100 degrees.  After two consecutive summers of not reaching 100 degrees, Pierre reached and surpassed 100 degrees several times this past summer.

The yearly precipitation was above normal for most locations across central and northeast South Dakota as well as west central Minnesota. The snowmelt in the spring and the summer thunderstorms led to flooding across parts of central and much of northeast South Dakota and west central Minnesota.  For 2010, most locations were from 3 to 7 inches above normal.  North central South Dakota actually went into drought for much of the summer of 2010. Mobridge’s yearly precipitation was at 16 inches or sixty-five hundredths below normal whereas, Wheaton and Watertown received almost 29 inches of precipitation for the year.

The biggest weather events of the year were the devastating Bowdle EF4 tornado in late May, the United States record 8-inch diameter and almost 2 pound hailstone that fell in Vivian, South Dakota in July.  The other big event for 2010 was the record surface low pressure area that moved across Minnesota in late October which brought very high winds gusting to over 70 mph to the region for two days causing damage across parts of the region.

Monthly Reviews: 

January Climate Information: January 2010 began with bitter cold air early in the month with lows of around 30 to 35 below zero across northeast South Dakota and west central Minnesota.  The lowest temperatures for the month across central and north central South Dakota were in the mid 20s to around 30 below zero.  Despite a mid and late January warm up with highs in the 20s and 30s along with some lower 40s, the month managed to finish out below normal across the area. The monthly average temperatures were from 1 to 3 degrees below normal for all locations. With a couple significant weather systems early and late in the month, January’s precipitation ranged from slightly above to much above normal across the area.  Northeast South Dakota and west central Minnesota were the wettest with around an inch or more of precipitation for the month.  Much of this precipitation came in the form of rain and freezing rain.

Cold and Snowy February: The below normal temperature and above normal snowfall trend continued for February across central, north central, and northeast South Dakota as well as west central Minnesota.  The average monthly temperatures ranged from around 6 degrees to nearly 12 degrees below normal for the month. The highest temperatures for the month reached only the lower 30s across the area.  Total snowfall for the month ranged from around 8 to 18 inches which is from 2 to 12 inches above normal.  With these cold temperatures and high snowfall amounts, several locations had one of their top fifteen coldest and snowiest Februarys on record.  The average February temperature for Pierre was only 12.9 degrees which was 11.5 degrees below normal.  The 12.9 degrees ranks as the 7^th coldest February at Pierre since records began.  In addition, Sisseton and Timber Lake both had their 11^th coldest February on record.  As for snowfall, locations in northeast South Dakota and west central Minnesota had one of their top ten snowiest Februarys on record. The 18 inches of snowfall at Sisseton ranked as the second snowiest February on record.   Both Wheaton, Minnesota and Watertown had their sixth snowiest February on record with 14.8 inches and 18.0 inches, respectively.

Warmer Than Normal April: Another above normal temperature month occurred across central and northeast South Dakota as well as west central Minnesota.  Temperatures for April were from 4 to nearly 8 degrees above normal across the area.  The warmest daily temperatures for the month were in the upper 70s to the lower 80s in the middle of April.  Along with these warm temperatures, very strong south winds from 35 to 45 mph gusting to 60 to 70 mph occurred on April 13^th.  The wind and warm temperatures also helped several fires to spread. The precipitation for April was near to above normal which was not good for the ongoing flooding situation, especially in northeast South Dakota.  Snowfall was pretty much non-existent for the month except for west of the Missouri River in north central South Dakota. Towards the end of the month, a large upper level low pressure area brought showers and thunderstorms to the region with rainfall amounts ranging from a quarter inch to over two inches in some locations.  In Brown County, Aberdeen received nearly 2.25 inches or rain over a two day period adding to the expansive and damaging flooding already occurring.  

Cooler Than Normal May: After a couple of months with above normal temperatures across the region, May 2010 across central and northeast South Dakota along with west central Minnesota had below normal temperatures.  The precipitation for May was generally above normal across the region.  Average temperatures for May ranged from 4 tenths to nearly 4 degrees below normal.   After a very warm April, widespread freezing temperatures occurred early in the month with lows in the mid 20s to the lower 30s on May 8^th and 9^th.  The high temperatures for May were in the upper 80s to the lower 90s which occurred at the end of the month. The rainfall amounts for May across the area were generally from a quarter of an inch to nearly 2 inches above normal.  Both Sisseton and Wheaton had below normal rainfall for the month.  In the Aberdeen area, where ongoing flooding continues to be an issue, May’s rainfall was 4.46 inches or 1.77 inches above normal.  On the cold side, Timber Lake in north central South Dakota had 1.2 inches of snowfall on May 7^th. The big story for the month of May was the damaging tornados in north central into northeast South Dakota touching down from Akaska to Bowdle to Hecla on May 22^nd.  Eight tornados touched down with the largest tornado being an EF4 tornado (winds 166-200 mph) which just missed the town of Bowdle. 

June Climate Information: June 2010 across central and northeast South Dakota as well as west central Minnesota was near to slightly below normal for temperatures.  High temperatures for the month were on the cool side for Wheaton, Pierre, and Kennebec with all locations from 3 to 4 degrees below normal.  Central and north central South Dakota finally had the heat turned up with locations topping out in the upper 90s to 100 degrees on June 30^th.  Pierre has not reached 100 degrees over the last two summers and has yet to hit the century mark this summer.  Some locations had below normal precipitation for June while others had much above normal precipitation for the month.  Kennebec had just over 6 inches of rainfall for the month which was over 3 inches above normal. Aberdeen was almost 2 inches above normal while Timber Lake was 1.54 inches below normal.

July Climate Information: The average temperatures for July 2010 across central and northeast South Dakota and west central Minnesota were near normal with average temperatures within one degree of normal. The highest temperatures for the month of July were in the mid to upper 90s with 105 and 106 degrees at Kennebec and Pierre, respectively. The total precipitation for July was also not far off from normal for most locations except for Sisseton and Kennebec. Sisseton was 1.25 inches below normal while Kennebec was 2.25 inches above normal. The big stories for the month of July across the area were the record breaking hail in central South Dakota, the dam failure in southeast Hand County, and Pierre finally surpassing the 100 degree mark.   On July 23rd, 8 inch diameter hail fell at Vivian, South Dakota breaking the U.S. record set in Aurora, Nebraska. The hailstone also broke the weight record weighing in at almost two pounds. On July 30th, very heavy rains from 5 to 10 inches brought flash flooding to southeast Hand County causing the Rose Hill dam to fail. Finally, after experiencing two consecutive summers without reaching 100 degrees, Pierre finally surpassed the century mark on July 17th reaching 106 degrees. 

August Climate Information: August 2010 heated up across central and northeast South Dakota and also dried out from the James River Valley west to areas either side of the Missouri River.  Average temperatures for August ranged from near normal to much above normal across the area.  Wheaton’s average August temperature was three tenths of a degree below normal while Watertown was almost five degrees above normal.  For the past few summers, 100 degree temperatures were unheard of across our area.  For this summer, 100 degree readings have occurred multiple times across central and north central South Dakota.  Mobridge, Pierre, Kennebec, and Timber Lake were at 100 degrees or above for a combined ten times in August.  The hottest day was August 27^th where Mobridge reached 106 degrees and Pierre reached 108 degrees.  The drier month along with the increasing drought area across north central South Dakota contributed to these warmer temperatures.  The air temperature warms up much more over a dry ground then over a wet ground. The rainfall for August was below normal across central and north central South Dakota from the James River Valley and west to the Missouri River. Rainfall amounts were around an inch to inch and a half below normal for the month.  This contributed to the expanding drought area across north central South Dakota in August.  With all of the dryness and warmer days along with periods of stronger winds and lower humidity, the fire danger has also become a bigger concern across the central and western parts of the region.   East of James River Valley into west central Minnesota, August rainfall ranged from near to much above normal as frequent thunderstorms rolled across this part of the region. Wheaton had almost 4 inches of rainfall in August.   

Very Wet and Cool September: September 2010 across central and northeast South Dakota as well as west central Minnesota was a very wet and cool month.  Average temperatures across the area ranged from a half degree to nearly 5 degrees below normal.  The average daily highs were especially cool ranging from 2 to over 7 degrees below normal.  Much of the coolness was related to many weather systems coming across the region bringing cloud cover along with abundant rainfall.  September rainfall amounts ranged from 2 to over 7 inches across the area which is from a half inch to over 5 inches above normal.  As a result, most of the locations had one of their top ten wettest Septembers on record. Watertown had its second wettest September on record while Wheaton had its third wettest.   Sisseton and Timber Lake both had their fifth wettest September on record while Pierre and Aberdeen finished the month with their tenth wettest September on record. 

Warmer and Drier October: October 2010 across central and northeast South Dakota as west central Minnesota was drier and much warmer than normal.  After a cool and very wet September, October had plenty of days with abundant sunshine along with very few precipitation days.   Average monthly temperatures were from one to three degrees above normal for October.  The warmest temperatures for October were early in the month and ranged from the mid 80s to the lower 90s.  October precipitation was generally from a half to an inch below normal across the area with a few locations near normal.  The big story for the month of October occurred at the end of the month when an intense surface low pressure area developed over the region.  This low pressure area brought very high winds of 35 to 45 mph with gusts to 60 to 70 mph to all of the region on October 26^thand 27^th.  Along with the high winds, snow from a trace to 2 inches fell across the area with 3 to 6 inches in the Sisseton Hills of northeast South Dakota. 

November: Dry With Near Normal Temperatures: November 2010 across central and northeast South Dakota as well as west central Minnesota started out very warm with much above normal temperatures and finished out the month colder than normal.  Overall, average temperatures for the month were generally from 1 degree above to 1 degree below normal for all locations.  Very warm temperatures occurred early in the month from the 6^th through the 10^th with highs in the upper 60s to the upper 70s.  Low temperatures for November were mainly in the single digits below zero towards the end of the month.  The big story for November was the dry conditions with much below normal precipitation across the region.  Snowfall for November was generally around 2 inches and below across the region.

All-Time December Record Snowfalls: All-time record snowfalls for December occurred for several locations across northeast South Dakota and west central Minnesota. The total December snowfall amounts ranged from nearly 25 inches at Aberdeen to 33 inches at Sisseton.  Watertown received 29 inches of snowfall for December while Wheaton recorded 31.1 inches of snowfall. These December snowfall amounts were only 10 inches or less off of the seasonal snowfall normals for Sisseton, Wheaton, and Watertown.  In central South Dakota, Pierre and Kennebec had one of their top ten snowiest Decembers on record.  The total snow water equivalent precipitation across the region was also way above normal ranging from just around an inch up to 2 ½ inches. December 2010 was also a very cold month for the entire area with average monthly temperatures ranging from nearly 3 degrees up to 6 degrees below normal.