2009 Climate Summary

The year of 2009 across central and north central South Dakota as well as west central Minnesota was dominated by northwest flow which brought cool to bitter cold air masses across the region from the Canada and the Arctic. Therefore, all locations across the area averaged from around 1 degree to 3.5 degrees below normal for 2009. The lowest temperature for the year occurred on January 15^th with the lows across the region in the 20s to 30s below zero. Aberdeen recorded a low temperature of 42 degrees below zero on this date.  It is also interesting to note in the 2009 the absence of 100 degree temperatures across the area.  In fact, the highest temperatures for the year were in the mid to upper 90s for all locations.

The year of 2009 was not only cooler than normal but also wetter than normal across central and northeast South Dakota as well as west central Minnesota.  The yearly total precipitation amounts were anywhere from a half inch to over 4 inches above normal.  As a result, flooding was an issue especially across northeast South Dakota and west central Minnesota.  

Monthly reviews: 

Wetter and Colder February: The month of February across central and northeast South Dakota as well as west central Minnesota had several large precipitation producing systems affect the area.  These systems were enough to bring the month of February above normal precipitation and snowfall for most locations across central and northeast South Dakota along with west central Minnesota. The first storm system in early February was quite unusual in that it was warm and produced mostly rain and quite of bit of rain especially for central and north central South Dakota.  Several locations had an inch or more of rainfall from this storm.  Mobridge had 1.28 inches of rainfall from February 8^th to the 9^th.  The other systems came at the end of the month and brought large snowfall amounts across central and northern South Dakota into west central Minnesota.  Snowfall amounts from 6 to as much as 14 inches were reported with the February 26^th and February 27^th storms.  February snowfall amounts ranged from near normal to over 10 inches above normal.  Sisseton, Wheaton, and Mobridge all had around 16 inches of snowfall for the month.  These snowfalls ranked as the 4^th snowiest February at Wheaton and Mobridge, the 7^th snowiest at Sisseton, and the 11^th snowiest February at Timber Lake on record.   As far as total precipitation, the 1.87 inches at Timber Lake was their 3rd wettest February and the 1.01 inches at Pierre was their 15^th wettest February on record.  Pierre and Mobridge also set daily maximum precipitation records on the 9^th. The temperatures for the month of February continued the trend of below normal across much of north central and northeast South Dakota along with west central Minnesota.  Temperatures ranged from 2 degrees below to as much as 7 degrees below normal for the month of February.  Again, Kennebec and Pierre were near to above normal for temperatures.  Kennebec set a record high of 64 degrees on the 6^th.   The snow cover continued to play a role and keeping the northern and eastern parts of the area colder than normal.

Cold and Wet March: The month of March was another below normal temperature and above normal precipitation month across most of central, north central, and northeast South Dakota as well as west central Minnesota. Monthly average temperatures ranged from 1 degree to over 7 degrees below normal across the region. Precipitation for the month of March was above normal and for some locations it was much above normal.  Watertown, Wheaton, and Sisseton were all around one inch above normal for precipitation. Locations in central and north central South Dakota ranged from just below to slightly above normal for precipitation. Several significant winter storms/blizzards during the month of March were responsible for the above normal snowfall across the region. Monthly snowfall amounts for the locations below ranged from 9 to 16 inches for March which was from 2 to 8 inches above normal. March came in with bitter cold temperatures with the lowest temperatures for the month recorded on the first. Low temperatures on March 1^st were from 15 to 25 degrees below zero across the area.  The winter storm/blizzard events for the month of March occurred on the 10^th and 11^th, 24^th, and the 30^th and 31^st. The end of March storm brought some very heavy snow to the area with amounts ranging from 8 to as much as 20 inches. The big story for the month of March was the warm up in the middle of the month and the subsequent rapid melt of the deep snow pack across the region. The result was flooding on most all of the rivers and streams across north central and northeast South Dakota as well as west central Minnesota. Minor to record flooding occurred on many of the rivers including the Moreau, Grand, Maple, Elm, Little Minnesota, Big Sioux, and the James River. With the additional snowfall and melt to come, rises on rivers and streams may occur again across the region.

A Cold Yet Drier April: April continued the string of below normal temperature months for much of central and northeast South Dakota as well as west central Minnesota.  Monthly temperatures for April were from over 1 to over 5 degrees below normal for locations across the area.  The average April temperature for Watertown was around 1 degree below normal compared to over 5 degrees below normal for Wheaton.  As far as precipitation, the string of above normal precipitation months came to an end as the precipitation for April was below normal for most locations across the region.  If it were not for a couple precipitation events, April would have been far below normal for precipitation.  Much below normal precipitation for April would have helped dry things out across the region after a wet and cold winter.  The monthly precipitation amounts were generally from a quarter inch to as much as an inch below normal.  Pierre and Aberdeen were the closest to normal precipitation with only a few hundredths of an inch below normal.  Also, the cooler than normal April temperatures did not allow for much drying to occur across the region. The month of April began with deep snow cover across the area from a late March storm along with cold temperatures.   A couple snow events occurred in April with monthly snowfall amounts ranging from 2 to 6 inches across most of the area.  Kennebec received nearly 11 inches of snowfall for the month of April.  The late March snow along with the additional April snow only added to the wet situation and ongoing flooding problems on the rivers and streams across much of the region.  In late April, a shower and thunderstorm event brought some large hail along with decent rainfall amounts  to mainly northeast  South Dakota and west central Minnesota.  Rainfall amounts ranged from a half inch to an inch and a quarter across this area. The coldest temperatures for the month occurred in the first few days with lows in the upper single digits to the mid teens.  Record or near record warmth occurred towards the end of the month as temperatures rose into the mid 80s to around 90 degrees on April 23rd.  On this day, Aberdeen, Pierre, and Mobridge broke their record highs while Wheaton tied its record high with a hot 91 degrees.  After this very warm day, much colder air pushed in and snow fell the very next day across the region with some locations receiving several inches. 

A Cold Yet Dry May: May continued the string of below normal temperatures for much of central and northeast South Dakota as well as west central Minnesota.  Monthly temperatures for May ranged from just below normal at Watertown to almost 5 degrees below normal at Wheaton.  May was also below normal for precipitation at all locations across the region, making this the second consecutive month.  The monthly precipitation amounts were generally from one inch to as much as two and a half inches below normal.  Mobridge was the closest to their normal precipitation, but was still almost an inch below normal.  Aberdeen, Pierre, and Kennebec were all more than two inches below normal. Several locations across northeastern South Dakota recorded their top 5 driest Mays on record. May was fairly quiet with regards to significant weather.  A storm system moved across central South Dakota on May 8^th and produced the best rainfall of the month for several locations. Rainfall amounts ranged from a half inch in Pierre and Timber Lake to over three-quarters of an inch in Mobridge.  This same area would see strong to severe storms four days later on May 12^th.   Hail, up to the size of quarters, and strong winds exceeding 60 mph were observed with the severe storms. Cool Canadian high pressure settled over the area on May 16^th and brought much below normal temperatures.  A few locations either tied or set record lows for this date.  The low of 29 degrees in Pierre broke their previous record of 35 degrees set back in 2002.  The cold air did not last long however, as warm air would return by the 18^th.  On May 19^th, temperatures soared into the low to mid 90s across the area, making this day the warmest of the month for many locations.  Aberdeen and Sisseton both reached 96 degrees, making this the warmest day of the year.  Watertown reached a high of 94 degrees, setting a new record.  The previous record high was 93 degrees set in 1934.

June, Another Cooler Than Normal Month: The string of below normal temperature months continued across central and northeast South Dakota as well as west central Minnesota.  For June 2009, temperatures again were well below normal for all locations across the area ranging from 2.4 degrees to 4.6 degrees below normal.  The highest temperatures for June were towards the end of the month with highs around 90 to 95 degrees.  Lows for June were recorded early on and were in the upper 30s to around 40 degrees. As far as precipitation for June, most locations had slightly above to much below normal rainfall with the exception of Kennebec.  Kennebec really stood out for the month of June with 5.11 inches of rainfall which was over 2 inches above normal. 

Record Cool Summer 2009: The summer (June-August) of 2009 was one of the coolest summers on record across central and northeast South Dakota as well as west central Minnesota. Prevailing northwest winds throughout the summer brought frequent shots of Canadian air into the region.  The average summer temperatures for locations across the region were from 3 to 5 degrees below normal.  All locations were among the top five coolest summers on record with none of the locations reaching 100 degrees from June through August. In fact, Pierre also did not reach 100 degrees in the summer of 2008. Since records began, Pierre has never had two consecutive summers that had not reached 100 degrees. As for precipitation, most locations were from near to much above normal for the summer of 2009 with Wheaton in west central Minnesota well below normal. Kennebec finished the summer of 2009 nearly 3 and a half inches above normal. Listed below are the summer 2009 temperature rankings for several locations across the area.  The summer period average temperature was for the months of June, July, and August. Kennebec:  The 68.6 temperature ranks as the 2^nd coldest on record. Mobridge:  The 65.6 temperature ranks as the 3^rd coldest on record. Timber Lake:  The 66.0 temperature ranks as the 3^rd coldest on record. Pierre:  The 68.4 temperature ranks as the 4^th coldest on record. Wheaton, MN:  The 65.6 ties for the 4^th coldest summer on record.  This tied with 2004. Sisseton:  The 65.5 ranks as the 4^th coldest on record.  2004 is the third coldest. Watertown:  The 64.6 ties for the 5^th coldest on record. Aberdeen:  The 65.4 ranks as the 5^th coldest on record.

Cool and Wet August: The below normal temperature trend continued across central and northeast South as well as west central Minnesota for the month of August. Temperatures for the month averaged from 2.5 to around 5 degrees below normal. The highest temperatures for the month were in the 90s with lows in the upper 30s to the mid 40s. Sisseton cooled to a chilly 37 degrees on August 30^th. Every location had above normal rainfall for August with Pierre and Sisseton nearing 2 inches above normal. On August 7^th, Sisseton had nearly 3 inches of rainfall.

Above Normal September: After a long string of months of below normal temperatures across central and northeast South Dakota as well as west central Minnesota, September had above normal temperatures across the area.  November of 2008 was the last time all locations recorded above normal temperatures.  Although, November 2008 was just a bump in the below normal temperature road as we have to go back to November 2007 when the temperatures were again all above normal across the area.  Since November of 2007, twenty of the twenty-one months have been overwhelming below normal across central and northeast South Dakota as well as west central Minnesota. For September of 2009, the average temperature was from 1.6 to 4.6 degrees above normal across the region. Watertown and Timber Lake were the most above normal.  The warmest temperatures for the month were in the mid 80s to around 90 degrees.  At the end of September, high pressure, clear skies, and light winds settled over the region bringing near freezing to below freezing temperatures.  Many locations experienced frost for the first time this year. The coldest locations were at Pierre and Kennebec where the temperature fell to 29 degrees at Pierre and 26 degrees at Kennebec. Precipitation across the area for September was generally near to below normal with Aberdeen over 2.5 inches above normal and Pierre and Kennebec nearly an inch below normal.

Record Cold and Wet October: October 2009 will be remembered as one the coldest Octobers on record along with one of the wettest.  The average temperature across the area for October ranged from 38 to 42 degrees which was from 6 to 9 degrees below normal.  Every location had one of their top five coldest Octobers on record.  Kennebec set their all-time coldest October on record with 41.6 degrees breaking the previous record by almost one degree.  The previous record for Kennebec was 42.5 degrees set in the 1917 and 2002.  The average daily high temperatures across the area were well below normal, anywhere from 11 to nearly 15 degrees below normal for the month.   Pierre, Sisseton, Timber Lake, and Mobridge all had their second coldest Octobers on record. Wheaton had their third coldest October while Aberdeen and Watertown had their fourth coldest October on record. October was also a very wet month with precipitation amounts ranging from 3 to over 7 inches across the region. These precipitation amounts were anywhere from 1 to over 5 inches above normal with several monthly precipitation records broken across northeast South Dakota and west central Minnesota.  Browns Valley, Minnesota received 7.36 inches of precipitation for October breaking the old record of 5.73 inches in 1998 by 1.63 inches.

Record Warm and Dry November: After a record wet and cold October, the month of November was just the opposite across central and northeast South Dakota as well as west central Minnesota with record warmth and little moisture.  Average temperatures for November were from 7 to 10 degrees above normal.  The highest temperatures for the month for all locations were in the 60s and 70s with even an 80 degree reading at Kennebec.  Wheaton had its third warmest November on record while Aberdeen and Watertown had their fourth warmest November on record.  Pierre, Sisseton, and Mobridge had their fifth warmest November on record while Timber Lake and Kennebec had their sixth warmest November on record. November was also a snowless month for many locations across central and northeast South Dakota along with west central Minnesota. The total precipitation for the month of November was well below normal for all locations with only a few hundredths recorded at Kennebec, Mobridge, and Timber Lake.  In fact, Timber Lake, Kennebec, and Mobridge ranked among their top fifteen driest Novembers on record. 

Record Cold and Snowy December: December 2009 across central and north central South Dakota as well as west central Minnesota was a very cold an snowy month with much of the snow coming from the Christmas Blizzard. Average temperatures for the month were from 4 to 8 degrees below normal with several locations having one of their top ten coldest Decembers on record. The locations in the top ten coldest Decembers were Pierre (sixth), Kennebec (ninth), and Sisseton (tenth). Mobridge and Timber Lake both had their eleventh coldest December on record. The Christmas blizzard brought anywhere from 8 to 24 inches of snowfall helping to break many of the December snowfall records.  Most locations finished the month with one of their top five snowiest Decembers on record.   The total snowfall amounts for the month ranged from 14 to 30 inches across central and northeast South Dakota as well as west central Minnesota.  Sisseton, Watertown, and Kennebec all had their snowiest December on record.  Pierre had its second snowiest December on record while Wheaton, Mobridge, and Timber Lake all had their third snowiest December.  Aberdeen finished the month with its eighth snowiest December on record.