National Weather Service United States Department of Commerce

June 2015 was a warmer than normal month across central and northeast South Dakota as well as west central Minnesota. Average monthly temperatures were anywhere from near normal to almost three and half degrees above normal. Everyone reached the mid to upper 90s for highs for the month with no one hundreds reported.  Precipitation across the region varied from above, near, to below normal ranging from 2.36 inches below at Sisseton to 2.59 inches above at Pierre.  Pierre received over 6 inches of rain during June. 

The highlights for severe weather took place in a back-to-back timeframe from June 19th through June 22nd.  The beginning of the first one took place across Sully, Hand, and Hyde counties during the afternoon of the 19th with severe weather and flash flooding.  Large hail up to 2 inches along with 5 to 6 inches of rainfall occurring in some locations with radar estimates much higher.  During the night of June 19th and 20th, a squall line of severe thunderstorms produced winds of over 90 mph mainly across Jones, Lyman, and Buffalo counties mainly along Interstate-90.  Numerous structures, campers, trees, semis, power lines, billboards, roads signs, grain bins, along with a trailer house were damaged or destroyed.  There was a fatality when the trailer house was destroyed in Fort Thompson.

The other severe event came within 72 hours from Sunday evening June 21st through Monday morning June 22nd.  First a bowing line of storms moved in from south central North Dakota impacting McPherson and Brown counties with hail up to baseball size at Richmond Lake. A couple supercells then tracked from Bath to Milbank producing large hail. The second shot during this event was the derecho, a particularly damaging and long-lived line of wind-producing thunderstorms that moved at 60 mph from western South Dakota into Stanley County.  A wind gust of 122 mph was measured near Hayes, unofficially.  One person was injured here as a camper rolled along with some grain bins destroyed and an office building moved. The storms raced east through Pierre and Fort Pierre with winds measured up to 81 mph at the Pierre Airport.  Widespread damage occurred with countless trees downed, a flipped mobile home and semis, along with several buildings damaged.  The storms then moved east to affect much of Lyman, Hyde, Hand, and Buffalo counties, the same counties that were affected a few days earlier.  The storms went on to produce widespread wind damage through southeast South Dakota, southern Minnesota, northern Iowa, and Illinois through the morning and afternoon hours on the 22nd.

 JUNE 2015

       

Temperature Data

Aberdeen

Sisseton

Wheaton

Watertown

Warmest Temperature / Date

98 / 9th

97 / 9th

94 / 10th

96 / 9th

Coldest Temperature / Date

48 / 12th

49 / 12th

47 / 1st

45 / 12th

Average High / Departure from Normal

81.6 / +4.2

80.0 / +2.7

76.6 / -0.7

78.2 / +1.5

Average Low / Departure from Normal

56.4 / +2.7

56.7 / +1.9

57.0 / +0.9

56.0 / +1.5

Monthly Average / Departure from Normal

69.0 / +3.4

68.3 / +2.2

66.8 / +0.1

67.1 / +1.5

Precipitation Data

       

Monthly Precipitation / Departure from Normal

2.10 / -1.60

1.38 / -2.36

4.43 / +0.45

2.93 / -0.65

Most Precipitation in 24 hours / Date

0.93 / 22nd

0.45 / 16th

1.07 / 7th

1.02 / 19-20th

         

Temperature Data

Pierre

Kennebec

Mobridge

Timber Lake

Warmest Temperature / Date

96 / 9th

99 / 9th  

95 / 27th,29th

93 / 29th

Coldest Temperature / Date

49 / 12th

46 / 12th

49 / 4th

47 / 1st

Average High / Departure from Normal

80.7 / +0.7

84.9 / +3.0

81.5 / +3.7

80.4 / +1.9

Average Low / Departure from Normal

57.5 / +2.1

57.1 / +1.3

56.8 / +3.0

55.4 / +1.8

Monthly Average / Departure from Normal

69.1 / +1.4

71.0 / +2.2

69.2 / +3.4

67.9 / +1.8

Precipitation Data

       

Monthly Precipitation / Departure from Normal

6.16 / +2.59

3.41 / +0.06

3.55 / +0.39

3.16 / -0.14

Most Precipitation in 24 hours / Date

2.06 / 19-20th

1.00 / 22nd

0.97 / 14th

0.59 / 25th