Illinois, 2023

Excessive Heat in Illinois, July 26 to 28, 2023

July 26 to 28, 2023 · NWS LOT · 22 events in 22 counties and zones

High temperatures ranging from the middle 80s to middle 90s and dewpoint temperatures in the upper 70s and lower 80s resulted in a few days of uncomfortably hot weather across northern and central Illinois from the 26th through the 28th. Each of the three days was progressively hotter than the previous with the 28th being the hottest.

Where it happened

Every event with a place to put it; 22 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

Open the live radar over this ground

The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
22

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS LOT wrote it up.

High temperatures ranging from the middle 80s to middle 90s and dewpoint temperatures in the upper 70s and lower 80s resulted in a few days of uncomfortably hot weather across northern and central Illinois from the 26th through the 28th. Each of the three days was progressively hotter than the previous with the 28th being the hottest. The afternoon of the 28th saw widespread heat indices in the 105-110 range with some spots seeing heat indices between 110 and 115 .

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Chicago, IL wrote its last area forecast discussion before the first event at Jul 26, 11:48 AM CST, 2 hours 12 minutes earlier.

Area forecast discussion, Jul 26, 11:48 AM CST, 2 hours 12 minutes before
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Hazardous weather outlook, Jul 26, 10:28 AM CST, 3 hours 32 minutes before
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In the hours before

Local storm report, Jul 26, 9:20 AM CST, 4 hours 40 minutes before
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Local storm report, Jul 26, 9:22 AM CST, 4 hours 38 minutes before
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Local storm report, Jul 26, 9:31 AM CST, 4 hours 29 minutes before
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Special weather statement, Jul 26, 10:01 AM CST, 3 hours 59 minutes before
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Local storm report, Jul 26, 10:16 AM CST, 3 hours 44 minutes before
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Local storm report, Jul 26, 11:48 AM CST, 2 hours 12 minutes before
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The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

22 excessive heat. Local standard time, as filed.

Excessive Heat, Winnebago

When
July 26, 2:00 PM CST to July 28, 8:00 PM CST
Where
Winnebago forecast zone
Reported by
ASOS
Coordinates
42.336, -89.161 (the zone’s center; the record gives no point)

Excessive Heat, Ogle

When
July 26, 2:00 PM CST to July 28, 8:00 PM CST
Where
Ogle forecast zone
Reported by
AWOS
Coordinates
42.043, -89.321 (the zone’s center; the record gives no point)

Excessive Heat, Lee

When
July 26, 2:00 PM CST to July 28, 8:00 PM CST
Where
Lee forecast zone
Reported by
AWOS
Coordinates
41.746, -89.300 (the zone’s center; the record gives no point)

Excessive Heat, La Salle

When
July 26, 2:00 PM CST to July 28, 8:00 PM CST
Where
La Salle forecast zone
Reported by
AWOS
Coordinates
41.344, -88.886 (the zone’s center; the record gives no point)

Excessive Heat, Grundy

When
July 26, 2:00 PM CST to July 28, 8:00 PM CST
Where
Grundy forecast zone
Reported by
AWOS
Coordinates
41.285, -88.418 (the zone’s center; the record gives no point)

Excessive Heat, Kendall

When
July 26, 2:00 PM CST to July 28, 8:00 PM CST
Where
Kendall forecast zone
Reported by
AWOS
Coordinates
41.591, -88.429 (the zone’s center; the record gives no point)

Excessive Heat, Eastern Will County

When
July 26, 2:00 PM CST to July 28, 9:00 PM CST
Where
Eastern Will County forecast zone
Reported by
AWOS
Coordinates
41.445, -87.979 (the zone’s center; the record gives no point)

Excessive Heat, Northern Will County

When
July 26, 2:00 PM CST to July 28, 9:00 PM CST
Where
Northern Will County forecast zone
Reported by
AWOS
Coordinates
41.445, -87.979 (the zone’s center; the record gives no point)

Excessive Heat, Southern Will County

When
July 26, 2:00 PM CST to July 28, 9:00 PM CST
Where
Southern Will County forecast zone
Reported by
AWOS
Coordinates
41.445, -87.979 (the zone’s center; the record gives no point)

Excessive Heat, Lake

When
July 26, 3:00 PM CST to July 28, 6:00 PM CST
Where
Lake forecast zone
Reported by
AWOS
Coordinates
42.349, -87.862 (the zone’s center; the record gives no point)

Excessive Heat, Boone

When
July 26, 3:00 PM CST to July 28, 8:00 PM CST
Where
Boone forecast zone
Reported by
AWOS
Coordinates
42.323, -88.823 (the zone’s center; the record gives no point)

Excessive Heat, De Kalb

When
July 26, 3:00 PM CST to July 28, 8:00 PM CST
Where
De Kalb forecast zone
Reported by
AWOS
Coordinates
41.894, -88.770 (the zone’s center; the record gives no point)

Excessive Heat, Ford

When
July 26, 3:00 PM CST to July 28, 8:00 PM CST
Where
Ford forecast zone
Reported by
AWOS
Coordinates
40.597, -88.223 (the zone’s center; the record gives no point)

Excessive Heat, Iroquois

When
July 26, 3:00 PM CST to July 28, 8:00 PM CST
Where
Iroquois forecast zone
Reported by
AWOS
Coordinates
40.747, -87.824 (the zone’s center; the record gives no point)

Excessive Heat, Kankakee

When
July 26, 3:00 PM CST to July 28, 8:00 PM CST
Where
Kankakee forecast zone
Reported by
AWOS
Coordinates
41.138, -87.862 (the zone’s center; the record gives no point)

Excessive Heat, Livingston

When
July 26, 3:00 PM CST to July 28, 8:00 PM CST
Where
Livingston forecast zone
Reported by
AWOS
Coordinates
40.892, -88.558 (the zone’s center; the record gives no point)

Excessive Heat, McHenry

When
July 26, 3:00 PM CST to July 28, 8:00 PM CST
Where
McHenry forecast zone
Reported by
AWOS
Coordinates
42.324, -88.452 (the zone’s center; the record gives no point)

Excessive Heat, Central Cook County

When
July 26, 3:00 PM CST to July 28, 8:00 PM CST
Where
Central Cook County forecast zone
Reported by
ASOS
Coordinates
41.895, -87.646 (the zone’s center; the record gives no point)

Excessive Heat, Du Page

When
July 26, 3:00 PM CST to July 28, 8:00 PM CST
Where
Du Page forecast zone
Reported by
ASOS
Coordinates
41.852, -88.086 (the zone’s center; the record gives no point)

Excessive Heat, Kane

When
July 26, 3:00 PM CST to July 28, 8:00 PM CST
Where
Kane forecast zone
Reported by
ASOS
Coordinates
41.939, -88.429 (the zone’s center; the record gives no point)

Excessive Heat, Northern Cook County

When
July 26, 3:00 PM CST to July 28, 8:00 PM CST
Where
Northern Cook County forecast zone
Reported by
ASOS
Coordinates
41.895, -87.646 (the zone’s center; the record gives no point)

Excessive Heat, Southern Cook County

When
July 26, 3:00 PM CST to July 28, 8:00 PM CST
Where
Southern Cook County forecast zone
Reported by
ASOS
Coordinates
41.895, -87.646 (the zone’s center; the record gives no point)

What these are

Excessive Heat
Heat at or above the local excessive heat warning criteria, or heat that caused deaths.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in Illinois in 2023Every state in 2023This day in weather historyWarnings in Illinois, July 2023

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-10-01. Each event’s entry at NCEI: 1136268, 1136269, 1136270, 1136271, 1136272, 1136273, 1136274, 1136275, 1136276, 1136277, 1136278, 1136279, 1136280, 1136281, 1136282, 1136283, 1136284, 1136285, 1136286, 1136287, 1136288, 1136289.