Warm and humid air invaded southeast Minnesota on July 17th and remained in place for the next three days. During this stretch, afternoon heat indices routinely topped out between 110 and 120. Little relief occurred at night, as overnight lows remained in the 70s. Most of the counties across southeast Minnesota opened cooling centers with Winona County reporting a total of 46 people using the cooling center. Several farmers loss some livestock due to the heat and at one feedlot near Harmony (Fillmore County), at least 24 head of cattle were lost. Rochester set known records for highest heat index ever (118) and highest dew point (83 deg F).

Excessive Heat in DODGE, MINNESOTA
From 17-JUL-11 11:30:00 to 20-JUL-11 18:30:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: AWOS

For an extended period between the 17th and 20th, afternoon heat indices routinely topped out between 105 and 110 with overnight low temperatures remaining above 75 degrees. The highest recorded heat index was 108 on the 19th and dew points reached a sultry 81.

Excessive Heat in MOWER, MINNESOTA
From 17-JUL-11 12:00:00 to 20-JUL-11 19:00:00 (CST-6)
Property damage: 35.00K
Crop damage: 0.00K
Reported by: AWOS

For an extended period between the 17th and 20th, afternoon heat indices routinely topped out between 110 and 115 with overnight low temperatures remaining above 75 degrees. The highest recorded heat index was 121 on both the 18th and 19th.  The highest dew points reached 84 degrees during this stretch.

Excessive Heat in OLMSTED, MINNESOTA
From 17-JUL-11 13:00:00 to 20-JUL-11 18:00:00 (CST-6)
Property damage: 23.00K
Crop damage: 0.00K
Reported by: ASOS

For an extended period between the 17th and 20th, afternoon heat indices routinely topped out between 110 and 115 with overnight low temperatures remaining above 75 degrees. The highest recorded heat index was 118 on the 18th, but dew points reached 83 degrees on the 18th and 19th.  Both these extreme heat index and dew points values were new records at the time.

Excessive Heat in HOUSTON, MINNESOTA
From 17-JUL-11 13:00:00 to 20-JUL-11 18:00:00 (CST-6)
Property damage: 12.00K
Crop damage: 0.00K
Reported by: Unknown

For an extended period between the 17th and 20th, afternoon heat indices routinely topped out between 110 and 115 with overnight low temperatures remaining above 75 degrees.

Excessive Heat in WINONA, MINNESOTA
From 17-JUL-11 13:00:00 to 20-JUL-11 18:00:00 (CST-6)
Property damage: 10.00K
Crop damage: 0.00K
Reported by: AWOS

For an extended period between the 17th and 20th, afternoon heat indices routinely topped out between 110 and 115 with overnight low temperatures remaining above 75 degrees. The highest recorded heat index was 114 on the 18th. A total of 46 people utilized a cooling center that was set up during the event.  Dew point values also topped off at 81 degrees on the 18th and 19th.

Excessive Heat in WABASHA, MINNESOTA
From 17-JUL-11 13:00:00 to 20-JUL-11 18:00:00 (CST-6)
Property damage: 6.00K
Crop damage: 0.00K
Reported by: Unknown

For an extended period between the 17th and 20th, afternoon heat indices routinely topped out between 110 and 115 with overnight low temperatures remaining above 75 degrees.

Excessive Heat in FILLMORE, MINNESOTA
From 17-JUL-11 13:30:00 to 20-JUL-11 18:00:00 (CST-6)
Property damage: 44.50K
Crop damage: 0.00K
Reported by: Unknown

For an extended period between the 17th and 20th, afternoon heat indices routinely topped out between 110 and 115 with overnight low temperatures remaining above 75 degrees. A local veterinarian reported that several of his clients lost livestock during the heat wave with one feedlot south of Harmony loosing at least 24 head of cattle.