Strong upper level ridge built up over the region from July 25th through 29th. This ushered in much warmer air and higher dewpoints. So heat index values 100+ were reported from July 25th through 29th. The hottest days were July 27th, 28th and 29th, so an excessive heat warning was issued for portions of northeast/east central Missouri and west central/southwest Illinois. At least 50 people were seen in hospital emergency room departments during this three day period in St. Louis County/City for heat-related illnesses.

Excessive Heat in GREENE, ILLINOIS
From 27-JUL-23 09:00:00 to 28-JUL-23 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Excessive heat across the county with highs mid to upper 90s degrees each day. Heat index values as high as 107 both days.

Excessive Heat in MONTGOMERY, ILLINOIS
From 27-JUL-23 09:00:00 to 28-JUL-23 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Excessive heat across the county with highs mid to upper 90s degrees each day. Heat index values as high as 107 both days.

Excessive Heat in CLINTON, ILLINOIS
From 27-JUL-23 09:00:00 to 29-JUL-23 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Excessive heat across the county with highs 95 to 100 each day. Heat index values as high as 110 each day.

Excessive Heat in WASHINGTON, ILLINOIS
From 27-JUL-23 09:00:00 to 29-JUL-23 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Excessive heat across the county with highs 95 to 100 each day. Heat index values as high as 110 each day.

Excessive Heat in FAYETTE, ILLINOIS
From 27-JUL-23 09:00:00 to 28-JUL-23 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Excessive heat across the county with highs mid to upper 90s degrees each day. Heat index values as high as 107 both days.

Excessive Heat in MONROE, ILLINOIS
From 27-JUL-23 09:00:00 to 29-JUL-23 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Excessive heat across the county with highs 95 to 100 each day. Heat index values as high as 110 each day.

Excessive Heat in BOND, ILLINOIS
From 27-JUL-23 09:00:00 to 29-JUL-23 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Excessive heat across the county with highs mid to upper 90s degrees each day. Heat index values as high as 110 each day.

Excessive Heat in MARION, ILLINOIS
From 27-JUL-23 09:00:00 to 29-JUL-23 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Excessive heat across the county with highs 95 to 100 each day. Heat index values as high as 110 each day.

Excessive Heat in JERSEY, ILLINOIS
From 27-JUL-23 09:00:00 to 29-JUL-23 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Excessive heat across the county with highs mid to upper 90s degrees each day. Heat index values as high as 107 each day.

Excessive Heat in ST. CLAIR, ILLINOIS
From 27-JUL-23 09:00:00 to 29-JUL-23 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Excessive heat across the county with highs 95 to 100 each day. Heat index values as high as 110 each day.

Excessive Heat in MADISON, ILLINOIS
From 27-JUL-23 09:00:00 to 29-JUL-23 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Excessive heat across the county with highs mid to upper 90s degrees each day. Heat index values as high as 110 each day.

Excessive Heat in BROWN, ILLINOIS
From 27-JUL-23 09:00:00 to 28-JUL-23 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Excessive heat across the county with highs up to 100 degrees each day. Heat index values as high as 114 both days.

Excessive Heat in RANDOLPH, ILLINOIS
From 27-JUL-23 09:00:00 to 29-JUL-23 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Excessive heat across the county with highs 95 to 100 each day. Heat index values as high as 110 each day.

Excessive Heat in ADAMS, ILLINOIS
From 27-JUL-23 09:00:00 to 28-JUL-23 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Excessive heat across the county with highs between 100 to 103 degrees each day. Heat index values as high as 114 both days.

Excessive Heat in MACOUPIN, ILLINOIS
From 27-JUL-23 09:00:00 to 28-JUL-23 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Excessive heat across the county with highs mid to upper 90s degrees each day. Heat index values as high as 107 both days.

Excessive Heat in CALHOUN, ILLINOIS
From 27-JUL-23 09:00:00 to 29-JUL-23 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Excessive heat across the county with highs mid to upper 90s degrees each day. Heat index values as high as 107 each day.

Excessive Heat in PIKE, ILLINOIS
From 27-JUL-23 09:00:00 to 28-JUL-23 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Excessive heat across the county with highs mid 90s to 101 degrees each day. Heat index values as high as 115 both days.