Alert archive / Illinois / Flash Flood Warnings / 2025
Flash Flood Warnings in Illinois, August 2025
32 flash flood warnings in August 2025. An alert counts here when it covered any part of the state, so the counties below add up to more than the state. The archive of flash flood warnings reaches back to 1986.
Flash Flood Warnings by county
Each county as a circle sized by its count in August 2025. Tap one for its archive.
- Flash Flood Warnings
- 32
- Busiest day
- August 19, 20258 flash flood warnings
Over time
By day
Days in UTC, the clock the archive keeps.
The alerts
Every alert, in the order issued. Times are local, Central Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 4, 2:54 PM CDT | Flash Flood Warning | PAH | Hamilton, Wayne | 2 hr |
| Aug 4, 3:20 PM CDT | Flash Flood Warning | PAH | Hamilton | 4 hr |
| Aug 4, 4:43 PM CDT | Flash Flood Warning | ILX | Crawford, Lawrence | 3 hr |
| Aug 6, 8:31 PM CDT | Flash Flood Warning | DVN | Mercer | 107 min |
| Aug 10, 4:18 AM CDT | Flash Flood Warning | DVN | Mercer, Rock Island | 5 hr |
| Aug 10, 7:01 AM CDT | Flash Flood Warning | DVN | Jo Daviess | 5 hr |
| Aug 12, 3:05 PM CDT | Flash Flood Warning | LOT | Cook, Will | 3 hr |
| Aug 12, 3:43 PM CDT | Flash Flood Warning | LSX | Madison, Saint Clair | 105 min |
| Aug 12, 5:04 PM CDT | Flash Flood Warning | LOT | Cook, DuPage, Will | 3 hr |
| Aug 12, 6:42 PM CDT | Flash Flood Warning | LOT | Livingston | 2 hr |
| Aug 16, 3:57 PM CDT | Flash Flood Warning | ILX | Vermilion | 2 hr |
| Aug 16, 5:11 PM CDT | Flash Flood Warning | LOT | DuPage | 2 hr |
| Aug 16, 7:03 PM CDT | Flash Flood Warning | ILX | Champaign, Vermilion | 117 min |
| Aug 17, 2:32 AM CDT | Flash Flood Warning | LOT | Cook, DuPage | 118 min |
| Aug 17, 3:36 AM CDT | Flash Flood Warning | LOT | Cook, DuPage, Kane, Kendall, Will | 114 min |
| Aug 17, 4:13 AM CDT | Flash Flood Warning | LOT | Kane, Kendall, Will | 2 hr |
| Aug 17, 4:20 AM CDT | Flash Flood Warning | LOT | Grundy, Iroquois, Kankakee, Kendall, Will | 3 hr |
| Aug 17, 3:11 PM CDT | Flash Flood Warning | LSX | Adams | 106 min |
| Aug 17, 7:17 PM CDT | Flash Flood Warning | LOT | LaSalle | 3 hr |
| Aug 17, 7:20 PM CDT | Flash Flood Warning | DVN | Bureau, Putnam | 2 hr |
| Aug 18, 5:26 PM CDT | Flash Flood Warning | LOT | DeKalb, Lee | 3 hr |
| Aug 18, 5:47 PM CDT | Flash Flood Warning | LOT | DuPage | 3 hr |
| Aug 18, 6:01 PM CDT | Flash Flood Warning | LOT | DeKalb, Lee | 3 hr |
| Aug 18, 6:52 PM CDT | Flash Flood Warning | LOT | Boone, Winnebago | 3 hr |
| Aug 18, 7:02 PM CDT | Flash Flood Warning | LOT | Cook, Will | 70 min |
| Aug 18, 7:07 PM CDT | Flash Flood Warning | LOT | LaSalle | 92 min |
| Aug 18, 7:37 PM CDT | Flash Flood Warning | LOT | McHenry | 3 hr |
| Aug 18, 7:38 PM CDT | Flash Flood Warning | LOT | LaSalle | 3 hr |
| Aug 18, 7:45 PM CDT | Flash Flood Warning | LOT | DeKalb, Kendall, LaSalle, Will | 84 min |
| Aug 18, 8:12 PM CDT | Flash Flood Warning | LOT | Cook, Will | 2 hr |
| Aug 18, 8:26 PM CDT | Flash Flood Warning | LOT | Cook | 3 hr |
| Aug 19, 12:03 AM CDT | Flash Flood Warning | LOT | Cook, Will | 87 min |
By county
Every county with at least one alert. A county page lists each alert that covered it.
- Will County9
- Cook County8
- DuPage County5
- Kendall County4
- LaSalle County4
- DeKalb County3
- Hamilton County2
- Mercer County2
- Vermilion County2
- Kane County2
- Lee County2
- Wayne County1
- Crawford County1
- Lawrence County1
- Rock Island County1
- Jo Daviess County1
- Madison County1
- Saint Clair County1
- Livingston County1
- Champaign County1
- Grundy County1
- Iroquois County1
- Kankakee County1
- Adams County1
- Bureau County1
- Putnam County1
- Boone County1
- Winnebago County1
- McHenry County1
Nearby
Alerts in force nowTornadoes on recordThe radar archive20242026
Sources
National Weather Service watches, warnings, advisories and statements from the Iowa Environmental Mesonet's VTEC archive, which reconstructs tornado, severe thunderstorm, flash flood and marine warnings back to 1986 from the NWS text archive. Storm Prediction Center watches and mesoscale discussions from SPC's archive through the Mesonet. County centers from the US Census Bureau. Rebuilt daily.