Alert archive / Illinois / Flash Flood Warnings / 2026

Flash Flood Warnings in Illinois, August 2026

56 flash flood warnings in August 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 August 2026. Tap one for its archive.

Flash Flood Warnings
56
Busiest day
August 15, 202614 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.

IssuedProductOfficeCountiesLasted
Aug 1, 6:25 AM CDTFlash Flood WarningLOTKendall, Will3 hr
Aug 1, 7:41 AM CDTFlash Flood WarningLOTCook, DuPage92 min
Aug 1, 1:46 PM CDTFlash Flood WarningILXVermilion3 hr
Aug 9, 10:10 PM CDTFlash Flood WarningLOTLee3 hr
Aug 9, 11:47 PM CDTFlash Flood WarningLOTGrundy, LaSalle, Livingston3 hr
Aug 10, 12:01 AM CDTFlash Flood WarningLOTLaSalle2 hr
Aug 10, 1:18 AM CDTFlash Flood WarningLOTFord, Kankakee, Livingston91 min
Aug 10, 1:52 AM CDTFlash Flood WarningLOTFord, Iroquois, Kankakee58 min
Aug 12, 7:18 AM CDTFlash Flood WarningDVNRock Island94 min
Aug 12, 9:37 AM CDTFlash Flood WarningLOTGrundy, Kankakee, Kendall, LaSalle, Will3 hr
Aug 13, 2:10 PM CDTFlash Flood WarningILXChampaign, DeWitt, McLean, Piatt2 hr
Aug 13, 2:47 PM CDTFlash Flood WarningILXChampaign, Vermilion2 hr
Aug 13, 11:21 PM CDTFlash Flood WarningILXKnox, Marshall, Peoria, Stark, Woodford4 hr
Aug 14, 12:40 AM CDTFlash Flood WarningILXVermilion12 hr
Aug 14, 12:48 AM CDTFlash Flood WarningLOTFord, Iroquois3 hr
Aug 14, 1:21 AM CDTFlash Flood Warning Considerable damage threatLOTFord, Iroquois6 hr
Aug 14, 1:38 AM CDTFlash Flood WarningILXChampaign, McLean7 hr
Aug 14, 2:59 AM CDTFlash Flood WarningILXChampaign, Vermilion6 hr
Aug 14, 3:44 AM CDTFlash Flood WarningDVNHenderson, Warren6 hr
Aug 14, 4:07 AM CDTFlash Flood WarningILXFulton, Knox, Peoria, Tazewell6 hr
Aug 14, 4:59 AM CDTFlash Flood WarningDVNHenderson, Mercer, Warren6 hr
Aug 14, 5:47 AM CDTFlash Flood WarningILXDeWitt, Piatt3 hr
Aug 14, 6:47 AM CDTFlash Flood WarningILXColes, Douglas, Edgar11 hr
Aug 14, 8:14 AM CDTFlash Flood WarningILXClark, Coles, Cumberland, Edgar3 hr
Aug 14, 10:00 AM CDTFlash Flood WarningILXCass, Fulton, Logan, Mason, Menard, Sangamon4 hr
Aug 14, 11:56 PM CDTFlash Flood WarningILXFulton, Knox, Mason, Peoria, Tazewell, Woodford7 hr
Aug 15, 12:58 AM CDTFlash Flood WarningDVNHancock6 hr
Aug 15, 1:09 AM CDTFlash Flood WarningILXMcLean6 hr
Aug 15, 1:50 AM CDTFlash Flood WarningLOTFord, Iroquois6 hr
Aug 15, 1:55 AM CDTFlash Flood WarningDVNHenderson, McDonough, Warren6 hr
Aug 15, 2:19 AM CDTFlash Flood WarningILXMcLean5 hr
Aug 15, 2:36 AM CDTFlash Flood Warning Considerable damage threatILXMcLean6 hr
Aug 15, 3:19 AM CDTFlash Flood WarningDVNHenderson5 hr
Aug 15, 3:23 AM CDTFlash Flood WarningILXChampaign5 hr
Aug 15, 3:23 AM CDTFlash Flood Warning Considerable damage threatLOTFord5 hr
Aug 15, 3:54 AM CDTFlash Flood WarningILXVermilion4 hr
Aug 15, 5:48 AM CDTFlash Flood Warning Considerable damage threatILXChampaign, Vermilion8 hr
Aug 15, 8:04 AM CDTFlash Flood WarningILXMcLean5 hr
Aug 15, 8:38 AM CDTFlash Flood Warning Considerable damage threatILXMcLean4 hr
Aug 15, 9:23 PM CDTFlash Flood WarningDVNMercer6 hr
Aug 19, 4:36 PM CDTFlash Flood WarningDVNHenderson2 hr
Aug 19, 5:43 PM CDTFlash Flood WarningILXKnox3 hr
Aug 19, 6:06 PM CDTFlash Flood WarningDVNMercer2 hr
Aug 19, 6:13 PM CDTFlash Flood WarningILXVermilion3 hr
Aug 19, 6:36 PM CDTFlash Flood WarningDVNMercer113 min
Aug 19, 6:52 PM CDTFlash Flood WarningILXTazewell, Woodford6 hr
Aug 19, 6:58 PM CDTFlash Flood WarningILXChampaign2 hr
Aug 19, 7:13 PM CDTFlash Flood WarningILXMarshall, Stark2 hr
Aug 19, 9:30 PM CDTFlash Flood WarningILXChampaign, DeWitt, Piatt3 hr
Aug 19, 10:44 PM CDTFlash Flood WarningILXChampaign3 hr
Aug 19, 11:32 PM CDTFlash Flood WarningILXChampaign, Vermilion3 hr
Aug 19, 11:42 PM CDTFlash Flood WarningPAHAlexander5 hr
Aug 19, 11:57 PM CDTFlash Flood WarningPAHPulaski6 hr
Aug 21, 8:12 PM CDTFlash Flood WarningDVNBureau, Putnam4 hr
Aug 21, 8:19 PM CDTFlash Flood WarningLOTLaSalle4 hr
Aug 21, 8:40 PM CDTFlash Flood WarningILXMarshall3 hr

By county

Every county with at least one alert. A county page lists each alert that covered it.

3 more counties

Nearby

Alerts in force nowTornadoes on recordThe radar archive2025

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.