3,164
Recorded events
102
Counties affected
30
Direct deaths
$274.9M
Property damage
Illinois flood history: 3,164 recorded events across 102 counties between 1996 and 2026.
Decade by decade
Illinois flood history by decade
The 2010s are the busiest decade on record with 1,266 reported flood events across Illinois. Earlier decades are thinner because systematic reporting for this hazard expanded over time, not because the weather was calmer.
County ranking
Counties with the most flood events in Illinois
| Rank | County | Events | Deaths | Damage | Span |
|---|---|---|---|---|---|
| #1 | Cook County | 209 | 2 | $7.2M | 1998–2026 |
| #2 | White County | 163 | 0 | $1.6M | 1999–2025 |
| #3 | Alexander County | 151 | 0 | $14.5M | 2002–2025 |
| #4 | Gallatin County | 95 | 0 | $2.2M | 1999–2025 |
| #5 | Wabash County | 89 | 1 | $392K | 1996–2024 |
| #6 | Jackson County | 89 | 0 | $4.0M | 2002–2024 |
| #7 | Will County | 88 | 0 | $25K | 1998–2026 |
| #8 | DuPage County | 77 | 1 | $0 | 1998–2026 |
| #9 | Pulaski County | 76 | 1 | $3.1M | 1998–2025 |
| #10 | Rock Island County | 71 | 2 | $1.9M | 1998–2024 |
| #11 | Massac County | 66 | 0 | $3.6M | 1996–2025 |
| #12 | Franklin County | 64 | 0 | $2.2M | 1996–2025 |
| #13 | Wayne County | 54 | 1 | $272K | 1998–2025 |
| #14 | Winnebago County | 46 | 0 | $8.0M | 2006–2026 |
| #15 | LaSalle County | 41 | 0 | $6.2M | 1998–2025 |
| #16 | Hancock County | 41 | 0 | $2.0M | 1998–2019 |
| #17 | Lake County | 41 | 0 | $600K | 2001–2026 |
| #18 | Pope County | 40 | 0 | $1.3M | 1999–2025 |
| #19 | Kane County | 36 | 0 | $5.0M | 1998–2024 |
| #20 | Mercer County | 35 | 0 | $575K | 1998–2024 |
| #21 | Henderson County | 34 | 0 | $875K | 2000–2024 |
| #22 | Whiteside County | 30 | 0 | $1.6M | 2000–2024 |
| #23 | Kankakee County | 29 | 0 | $1.6M | 1998–2025 |
| #24 | Iroquois County | 26 | 0 | $4.5M | 1998–2023 |
| #25 | Livingston County | 25 | 1 | $2.3M | 1998–2025 |
Significant events
Deadliest flood events in Illinois
| Date | County | Scale | Deaths | Injuries |
|---|---|---|---|---|
| Dec 27, 2015 | Christian County | — | 4 | 0 |
| Mar 18, 2008 | Jefferson County | — | 2 | 0 |
| May 16, 2009 | Fulton County | — | 1 | 0 |
| Apr 3, 1999 | Rock Island County | — | 1 | 0 |
| Apr 1, 2019 | Rock Island County | — | 1 | 0 |
| Jul 16, 2021 | Jefferson County | — | 1 | 0 |
| May 1, 2017 | Saline County | — | 1 | 0 |
| May 11, 2015 | Clinton County | — | 1 | 0 |
| Jun 5, 2008 | Coles County | — | 1 | 0 |
| Jul 7, 2016 | Johnson County | — | 1 | 1 |