Alert archive / Illinois / Flash Flood Warnings / 2026
Flash Flood Warnings in Illinois, April 2026
27 flash flood warnings in April 2026. 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 April 2026. Tap one for its archive.
- Flash Flood Warnings
- 27
- Busiest day
- April 27, 20269 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 |
|---|---|---|---|---|
| Apr 3, 7:05 PM CDT | Flash Flood Warning | ILX | McLean, Tazewell, Woodford | 3 hr |
| Apr 3, 7:54 PM CDT | Flash Flood Warning | ILX | McLean, Woodford | 3 hr |
| Apr 3, 8:08 PM CDT | Flash Flood Warning | LOT | Livingston | 6 hr |
| Apr 3, 9:46 PM CDT | Flash Flood Warning | LOT | Grundy, Kankakee, Livingston, Will | 4 hr |
| Apr 14, 7:12 PM CDT | Flash Flood Warning | DVN | Jo Daviess | 3 hr |
| Apr 14, 7:58 PM CDT | Flash Flood Warning | DVN | Jo Daviess, Stephenson | 3 hr |
| Apr 14, 8:37 PM CDT | Flash Flood Warning | LOT | Boone, Winnebago | 3 hr |
| Apr 14, 10:51 PM CDT | Flash Flood Warning | LOT | Cook, DuPage | 3 hr |
| Apr 15, 7:00 PM CDT | Flash Flood Warning | DVN | Jo Daviess | 4 hr |
| Apr 15, 7:14 PM CDT | Flash Flood Warning | DVN | Jo Daviess, Stephenson | 3 hr |
| Apr 15, 8:14 PM CDT | Flash Flood Warning | DVN | Carroll, Jo Daviess | 3 hr |
| Apr 15, 8:27 PM CDT | Flash Flood Warning | LOT | Boone, Winnebago | 4 hr |
| Apr 17, 2:23 PM CDT | Flash Flood Warning | DVN | Jo Daviess | 6 hr |
| Apr 17, 7:26 PM CDT | Flash Flood Warning | LOT | Winnebago | 4 hr |
| Apr 17, 8:12 PM CDT | Flash Flood Warning | LOT | Boone, Lake, McHenry | 6 hr |
| Apr 27, 9:54 AM CDT | Flash Flood Warning | DVN | Hancock | 104 min |
| Apr 27, 10:04 AM CDT | Flash Flood Warning | ILX | Sangamon | 2 hr |
| Apr 27, 1:07 PM CDT | Flash Flood Warning | LSX | Fayette, Montgomery | 7 hr |
| Apr 27, 1:11 PM CDT | Flash Flood Warning | ILX | Clay, Cumberland, Effingham, Jasper, Shelby | 19 hr |
| Apr 27, 4:52 PM CDT | Flash Flood Warning | LSX | Adams, Pike | 4 hr |
| Apr 27, 5:20 PM CDT | Flash Flood Warning | LSX | Brown, Pike | 3 hr |
| Apr 27, 5:32 PM CDT | Flash Flood Warning | LSX | Jersey | 5 hr |
| Apr 27, 5:50 PM CDT | Flash Flood Warning | ILX | Cass, Menard, Morgan, Sangamon, Scott | 2 hr |
| Apr 27, 6:47 PM CDT | Flash Flood Warning | LSX | Macoupin | 5 hr |
| Apr 27, 7:16 PM CDT | Flash Flood Warning | LSX | Montgomery | 5 hr |
| Apr 27, 7:59 PM CDT | Flash Flood Warning | LSX | Fayette | 6 hr |
| Apr 27, 9:33 PM CDT | Flash Flood Warning | ILX | Crawford, Jasper | 3 hr |
By county
Every county with at least one alert. A county page lists each alert that covered it.
- Jo Daviess County6
- Boone County3
- Winnebago County3
- McLean County2
- Woodford County2
- Livingston County2
- Stephenson County2
- Sangamon County2
- Fayette County2
- Montgomery County2
- Jasper County2
- Pike County2
- Tazewell County1
- Grundy County1
- Kankakee County1
- Will County1
- Cook County1
- DuPage County1
- Carroll County1
- Lake County1
- McHenry County1
- Hancock County1
- Clay County1
- Cumberland County1
- Effingham County1
- Shelby County1
- Adams County1
- Brown County1
- Jersey County1
- Cass County1
- Menard County1
- Morgan County1
- Scott County1
- Macoupin County1
- Crawford County1
Nearby
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. Warning verification from the Mesonet's Cow. Rebuilt daily.