Most Flood-Prone Counties in Illinois

Based on NOAA Storm Events Database records from 1996 to 2025, these are the Illinois counties with the most recorded flood events. Cook County tops the list with 393 events. The data includes river floods, flash floods, coastal flooding, and hurricane-related flooding.

Rank	County	Total Events	River Floods	Flash Floods
1	Cook County	393	206	184
2	Alexander County	241	220	21
3	White County	227	202	25
4	Jackson County	203	159	44
5	Gallatin County	171	149	22
6	Will County	151	86	65
7	DuPage County	144	81	63
8	Pulaski County	137	123	14
9	Massac County	126	107	19
10	Franklin County	125	86	39
11	Wabash County	122	104	18
12	Rock Island County	119	81	38
13	Wayne County	104	68	36
14	Hancock County	94	57	37
15	Lake County	91	39	47
16	Winnebago County	88	53	35
17	LaSalle County	81	45	36
18	Sangamon County	80	15	65
19	Pope County	78	60	18
20	McDonough County	76	31	45
21	Effingham County	74	15	59
22	Champaign County	71	7	64
23	Fulton County	69	19	50
24	Kane County	69	40	29
25	Union County	69	43	26
26	Clay County	68	11	57
27	Williamson County	68	28	40
28	Shelby County	63	10	53
29	Saline County	63	20	43
30	Whiteside County	62	39	23
31	Henry County	61	25	36
32	Jo Daviess County	61	20	41
33	Perry County	60	20	40
34	Henderson County	60	41	19
35	Vermilion County	59	6	53
36	Hardin County	58	46	12
37	St. Clair County	58	14	44
38	Kankakee County	56	32	24
39	Stephenson County	56	16	40
40	Mercer County	55	42	13
41	Crawford County	55	12	43
42	Iroquois County	54	29	25
43	Christian County	53	7	46
44	Coles County	52	11	41
45	Lawrence County	50	11	39
46	Carroll County	49	19	30
47	Jasper County	49	9	40
48	Jefferson County	49	15	34
49	Peoria County	49	10	39
50	Logan County	48	5	43
51	Ogle County	48	22	26
52	Morgan County	47	15	32
53	Hamilton County	47	16	31
54	DeKalb County	46	19	27
55	Livingston County	46	26	20
56	Tazewell County	46	10	36
57	Knox County	45	11	34
58	McLean County	45	7	38
59	Macon County	45	3	42
60	Schuyler County	45	13	32
61	Woodford County	45	12	33
62	McHenry County	43	26	17
63	Edgar County	42	5	37
64	Grundy County	42	25	17
65	Scott County	42	11	31
66	Clark County	41	10	31
67	Madison County	40	13	27
68	Cumberland County	38	9	29
69	Kendall County	38	18	20
70	Richland County	38	6	32
71	Adams County	37	12	25
72	Ford County	36	19	17
73	Cass County	36	11	25
74	Douglas County	35	9	26
75	Jersey County	35	19	16
76	Boone County	34	20	14
77	Marion County	34	3	31
78	Marshall County	33	12	21
79	Lee County	31	13	18
80	Randolph County	31	12	19
81	Bureau County	31	5	26
82	Monroe County	31	12	19
83	Edwards County	30	14	16
84	Moultrie County	30	7	23
85	Calhoun County	28	15	13
86	Macoupin County	28	1	27
87	Mason County	28	10	18
88	Pike County	28	17	11
89	Fayette County	26	5	21
90	Johnson County	26	12	14
91	Menard County	26	3	23
92	Warren County	26	7	19
93	Piatt County	24	4	20
94	Stark County	23	5	18
95	Clinton County	23	3	20
96	Montgomery County	21	1	20
97	Bond County	21	2	19
98	De Witt County	20	2	18
99	Brown County	18	7	11
100	Greene County	18	6	12
101	Washington County	18	4	14
102	Putnam County	14	3	11

Source: NOAA Storm Events Database (1996–2025).

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