Flash Flood Warnings in Illinois
3,809 flash flood warnings since 1986. 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 since 1986. Tap one for its archive.
- Flash Flood Warnings
- 3,809
- Busiest year
- 2026218 flash flood warnings
- Average year
- 93over 41 years on file
Over time
By year
Before October 2007 these were issued for whole counties, and a storm crossing three counties was often three warnings; since then one polygon follows the storm. The count changed with the practice, not only with the weather.
By month of the year
By county
Every county with at least one alert. A county page lists each alert that covered it.
- Cook County227
- Will County153
- DuPage County130
- Saint Clair County129
- Sangamon County127
- Champaign County126
- Tazewell County121
- Vermilion County118
- Madison County117
- Fulton County114
- Effingham County114
- Jackson County111
- Clay County109
- Jasper County108
- Williamson County108
- Peoria County106
- Kane County105
- Hancock County104
- White County103
- Monroe County102
- Iroquois County102
- Rock Island County101
- Woodford County99
- Saline County96
- Fayette County96
- Adams County95
- Jo Daviess County95
- McLean County95
- Pope County95
- DeKalb County92
- LaSalle County91
- Union County91
- Logan County90
- McDonough County90
- Winnebago County89
- Gallatin County89
- Franklin County89
- Clinton County88
- Perry County87
- Mason County87
62 more counties
- Wayne County87
- Crawford County87
- Edgar County86
- Knox County86
- Shelby County86
- Massac County85
- Wabash County85
- Morgan County85
- Boone County84
- Coles County84
- Kendall County83
- Alexander County83
- Randolph County81
- Lawrence County81
- Kankakee County81
- Marion County80
- Edwards County80
- Bond County80
- Livingston County80
- Johnson County80
- Ford County79
- Richland County79
- Grundy County79
- Hamilton County79
- Clark County78
- Macon County78
- Christian County77
- Henderson County77
- McHenry County76
- Montgomery County75
- Ogle County75
- Piatt County75
- Cumberland County74
- Jefferson County73
- Macoupin County72
- Pulaski County72
- Henry County71
- Lake County71
- Schuyler County71
- Calhoun County70
- Lee County68
- Carroll County66
- Marshall County66
- Pike County65
- Whiteside County65
- Stephenson County65
- Washington County65
- Hardin County64
- Menard County63
- Warren County62
- DeWitt County60
- Jersey County59
- Bureau County58
- Cass County57
- Moultrie County57
- Scott County56
- Mercer County55
- Douglas County55
- Stark County48
- Greene County47
- Brown County46
- Putnam County37
The latest flash flood warnings
The most recent on file, newest first.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 20, 5:12 AM CDT | Flash Flood Warning | DVN | Jo Daviess | 4 hr |
| Sep 20, 2:12 AM CDT | Flash Flood Warning | LOT | DeKalb, LaSalle, Lee | 5 hr |
| Sep 20, 1:38 AM CDT | Flash Flood Warning | DVN | Bureau, Henry, Mercer, Rock Island, Whiteside | 6 hr |
| Sep 19, 4:19 AM CDT | Flash Flood Warning | DVN | Jo Daviess, Stephenson | 6 hr |
| Sep 17, 7:07 AM CDT | Flash Flood Warning | LOT | DeKalb, LaSalle, Lee | 2 hr |
| Aug 21, 8:40 PM CDT | Flash Flood Warning | ILX | Marshall | 3 hr |
| Aug 21, 8:19 PM CDT | Flash Flood Warning | LOT | LaSalle | 4 hr |
| Aug 21, 8:12 PM CDT | Flash Flood Warning | DVN | Bureau, Putnam | 4 hr |
| Aug 19, 11:57 PM CDT | Flash Flood Warning | PAH | Pulaski | 6 hr |
| Aug 19, 11:42 PM CDT | Flash Flood Warning | PAH | Alexander | 5 hr |
| Aug 19, 11:32 PM CDT | Flash Flood Warning | ILX | Champaign, Vermilion | 3 hr |
| Aug 19, 10:44 PM CDT | Flash Flood Warning | ILX | Champaign | 3 hr |
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. Rebuilt daily.