Heat indices peaked around 105 degrees during the afternoon. A total eclipse of the sun during the afternoon helped to keep temperatures and heat indices from climbing higher. At a music festival near Marion, 15 people had to be treated for heat-related illnesses.  The peak heat indices were 107 degrees at Mount Vernon and Cairo, 106 at Carmi and Fairfield, and 105 at Carbondale and Harrisburg. A strong 500 mb ridge over the southeast U.S. and Lower Mississippi Valley resulted in hot and humid weather. Surface high pressure over the central Appalachian Mountains produced a south wind flow of hot and humid air.

Heat in WABASH, ILLINOIS
From 21-AUG-17 11:00:00 to 21-AUG-17 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Heat in WAYNE, ILLINOIS
From 21-AUG-17 11:00:00 to 21-AUG-17 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Heat in WHITE, ILLINOIS
From 21-AUG-17 11:00:00 to 21-AUG-17 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Heat in WILLIAMSON, ILLINOIS
From 21-AUG-17 11:00:00 to 21-AUG-17 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Heat in ALEXANDER, ILLINOIS
From 21-AUG-17 11:00:00 to 21-AUG-17 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Heat in EDWARDS, ILLINOIS
From 21-AUG-17 11:00:00 to 21-AUG-17 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Heat in FRANKLIN, ILLINOIS
From 21-AUG-17 11:00:00 to 21-AUG-17 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Heat in GALLATIN, ILLINOIS
From 21-AUG-17 11:00:00 to 21-AUG-17 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Heat in HAMILTON, ILLINOIS
From 21-AUG-17 11:00:00 to 21-AUG-17 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Heat in HARDIN, ILLINOIS
From 21-AUG-17 11:00:00 to 21-AUG-17 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Heat in JACKSON, ILLINOIS
From 21-AUG-17 11:00:00 to 21-AUG-17 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Heat in JEFFERSON, ILLINOIS
From 21-AUG-17 11:00:00 to 21-AUG-17 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Heat in JOHNSON, ILLINOIS
From 21-AUG-17 11:00:00 to 21-AUG-17 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Heat in MASSAC, ILLINOIS
From 21-AUG-17 11:00:00 to 21-AUG-17 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Heat in PERRY, ILLINOIS
From 21-AUG-17 11:00:00 to 21-AUG-17 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Heat in POPE, ILLINOIS
From 21-AUG-17 11:00:00 to 21-AUG-17 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Heat in PULASKI, ILLINOIS
From 21-AUG-17 11:00:00 to 21-AUG-17 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Heat in SALINE, ILLINOIS
From 21-AUG-17 11:00:00 to 21-AUG-17 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Heat in UNION, ILLINOIS
From 21-AUG-17 11:00:00 to 21-AUG-17 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS