Heat, Bureau
- When
- July 25, 4:00 AM CST to July 27, 8:00 PM CST
- Where
- Bureau forecast zone
- Coordinates
- 41.404, -89.529 (the zone’s center; the record gives no point)
Heat in Illinois, July 25 to 27, 1997
Heat and high humidity teamed together produced excessive heat index values reaching 105 to 110 during the day. This came in the middle of an otherwise much cooler than normal summer and many claimed that their bodies were not properly acclimated and therefore unprepared for the sudden spike in temperatures and humidity.
Where it happened
Every event with a place to put it; 13 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
The toll
- Deaths
- 0
- Injuries
- 0
- Property damage
- None recorded
- Crop damage
- None recorded
- Events
- 13
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 DVN wrote it up.
Heat and high humidity teamed together produced excessive heat index values reaching 105 to 110 during the day. This came in the middle of an otherwise much cooler than normal summer and many claimed that their bodies were not properly acclimated and therefore unprepared for the sudden spike in temperatures and humidity.
The radar
The national radar mosaic for the moment the first event began.
Event by event
13 heat. Local standard time, as filed.
Heat, Carroll
- When
- July 25, 4:00 AM CST to July 27, 8:00 PM CST
- Where
- Carroll forecast zone
- Coordinates
- 42.069, -89.934 (the zone’s center; the record gives no point)
Heat, Hancock
- When
- July 25, 4:00 AM CST to July 27, 8:00 PM CST
- Where
- Hancock forecast zone
- Coordinates
- 40.404, -91.165 (the zone’s center; the record gives no point)
Heat, Henderson
- When
- July 25, 4:00 AM CST to July 27, 8:00 PM CST
- Where
- Henderson forecast zone
- Coordinates
- 40.818, -90.925 (the zone’s center; the record gives no point)
Heat, Henry
- When
- July 25, 4:00 AM CST to July 27, 8:00 PM CST
- Where
- Henry forecast zone
- Coordinates
- 41.353, -90.131 (the zone’s center; the record gives no point)
Heat, Jo Daviess
- When
- July 25, 4:00 AM CST to July 27, 8:00 PM CST
- Where
- Jo Daviess forecast zone
- Coordinates
- 42.366, -90.212 (the zone’s center; the record gives no point)
Heat, McDonough
- When
- July 25, 4:00 AM CST to July 27, 8:00 PM CST
- Where
- McDonough forecast zone
- Coordinates
- 40.456, -90.678 (the zone’s center; the record gives no point)
Heat, Mercer
- When
- July 25, 4:00 AM CST to July 27, 8:00 PM CST
- Where
- Mercer forecast zone
- Coordinates
- 41.205, -90.741 (the zone’s center; the record gives no point)
Heat, Putnam
- When
- July 25, 4:00 AM CST to July 27, 8:00 PM CST
- Where
- Putnam forecast zone
- Coordinates
- 41.205, -89.286 (the zone’s center; the record gives no point)
Heat, Rock Island
- When
- July 25, 4:00 AM CST to July 27, 8:00 PM CST
- Where
- Rock Island forecast zone
- Coordinates
- 41.467, -90.567 (the zone’s center; the record gives no point)
Heat, Stephenson
- When
- July 25, 4:00 AM CST to July 27, 8:00 PM CST
- Where
- Stephenson forecast zone
- Coordinates
- 42.352, -89.662 (the zone’s center; the record gives no point)
Heat, Warren
- When
- July 25, 4:00 AM CST to July 27, 8:00 PM CST
- Where
- Warren forecast zone
- Coordinates
- 40.849, -90.615 (the zone’s center; the record gives no point)
Heat, Whiteside
- When
- July 25, 4:00 AM CST to July 27, 8:00 PM CST
- Where
- Whiteside forecast zone
- Coordinates
- 41.756, -89.914 (the zone’s center; the record gives no point)
What these are
- Heat
- Heat below excessive heat criteria that still caused deaths, injuries or significant impacts.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
- Tornadoes and Flooding in Wisconsin, July 25, 1997
- Heat in Iowa, July 25 to 27, 1997
- Heat in Illinois, July 25 to 28, 1997
- Damaging Winds in South Dakota, July 25, 1997
- Damaging Wind in Minnesota, July 25, 1997
- Heat in Kentucky, July 25 to 28, 1997
- Hail and Damaging Winds in North Dakota, July 25, 1997
- Damaging Winds in Minnesota, July 25, 1997
- Hail and Damaging Winds in South Dakota, July 25 to 26, 1997
- Lightning Strike in New Mexico, July 25, 1997
- Hail and Damaging Winds in Nebraska, July 25, 1997
- Hail and Damaging Winds in South Dakota, July 25, 1997
More
Every storm in Illinois in 1997Every state in 1997This day in weather historyWarnings in Illinois, July 1997
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 2026-09-24. Each event’s entry at NCEI: 5601703, 5601704, 5601705, 5601706, 5601707, 5601708, 5601709, 5601710, 5601711, 5601712, 5601713, 5603928, 5603929.