National Weather Service Weather Forecast Office

The below normal temperature trend continued across central, north central, and northeast South Dakota as well as west central Minnesota for July.  In fact, July 2009 was one of the coolest Julys on record for many locations across the area.  A large upper low pressure trough across eastern Canada and the eastern United States kept the flow over the region out of the northwest with cool Canadian air dominating the area throughout July.  Average July temperatures ranged from around 4 degrees to nearly 7 degrees below normal.  In a normal July, 90s and even a few 100s are common across the area and for many locations in eastern South Dakota and west central Minnesota,  90 degrees was not achieved.  Even in central South Dakota, Pierre has failed again to reach 100 degrees so far this summer.  In Aberdeen, it has been only the fourth time since 1893 that the temperature in July has failed to reach 90 degrees. The 83 degree reading at Watertown on July 2nd was the coolest maximum high temperature for July at Watertown since 1893.

All of the locations in the table below experienced one of their top five coolest Julys on record.  Kennebec had their second coolest July on record while Wheaton and Sisseton had their third coolest. Pierre, Watertown, and Mobridge all experienced their fourth coolest July with Aberdeen and Timber Lake having their fifth coolest July on record.  Also, throughout the month of July several record lows and record low highs were set across the area.

As for July’s precipitation, rainfall amounts ranged from just above normal to much below normal for locations across the area.  In northeast South Dakota and west central Minnesota, both Sisseton and Wheaton were the driest with around 2 inches below normal for the month.