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.

Temperature Data	Aberdeen	Sisseton	Wheaton	Watertown
Warmest Temperature/Date	92 6/26; 8/12	93 6/26	94 8/13	90 6/26; 8/12
Coldest Temperature/Date	38 6/4	37 6/3	41 6/3; 6/6	39 6/3
Seasonal Average High/Departure from Normal	77.4 / -4.9	76.4 / -5.0	76 / -6.9	75.1 / -4.8
Seasonal Average Low/Departure from Normal	53.5 / -3.8	54.6 / -3.3	55.1 / -3.8	54.1 / -1.8
Seasonal Average/Departure from Normal	65.4 / -4.4	65.5 / -4.2	65.6 / -5.3	64.6 / -3.3
Precipitation Data
Seasonal Precipitation / Departure from Normal	9.16 / +0.33	7.91 / -1.11	6.24 / -3.17	9.66 / -0.11
Most Precipitation in One Day/Date	0.97 6/16	2.97 8/7	0.93 8/16	1.17 8/18

Temperature Data	Pierre	Kennebec	Mobridge	Timber Lake
Warmest Temperature/Date	97 7/26; 8/2; 8/12	97 8/2	93 7/23	98 8/12
Coldest Temperature/Date	42 6/6; 6/11	41 6/5	38 6/4; 6/11	38 6/4; 6/6
Seasonal Average High/Departure from Normal	81.2 / -5.0	81.9 / -6.2	77.9 / -5.0	78.9 / -3.6
Seasonal Average Low/Departure from Normal	55.6 / -3.7	55.2 / -3.9	53.3 / -5.2	53.1 / -3.9
Seasonal Average/Departure from Normal	68.4 / -4.4	68.6 / -5.0	65.6 / -5.1	66.0 / -3.8
Precipitation Data
Seasonal Precipitation / Departure from Normal	8.08 / -0.02	11.15 / +3.37	7.73 / +0.65	9.10 / +1.58
Most Precipitation in One Day/Date	1.64 8/15	1.78 6/27	1.11 7/14	1.65 7/13

Return to News Archive

National Weather Service Weather Forecast Office

Record Cool Summer 2009