Most Flood-Prone Counties in Ohio

Based on NOAA Storm Events Database records from 1996 to 2025, these are the Ohio counties with the most recorded flood events. Hamilton County tops the list with 257 events. The data includes river floods, flash floods, coastal flooding, and hurricane-related flooding.

Rank	County	Total Events	River Floods	Flash Floods
1	Hamilton County	257	111	146
2	Washington County	204	171	33
3	Franklin County	175	108	67
4	Scioto County	166	92	74
5	Warren County	163	99	64
6	Clermont County	154	66	88
7	Belmont County	147	49	98
8	Cuyahoga County	128	30	97
9	Athens County	125	72	53
10	Montgomery County	122	75	47
11	Adams County	121	61	60
12	Meigs County	118	85	33
13	Ross County	117	77	40
14	Hocking County	115	75	40
15	Brown County	111	53	58
16	Gallia County	108	66	42
17	Butler County	107	52	55
18	Coshocton County	107	37	70
19	Noble County	106	51	55
20	Tuscarawas County	105	37	68
21	Lawrence County	105	61	44
22	Mercer County	105	78	27
23	Licking County	102	66	36
24	Logan County	102	63	39
25	Vinton County	100	56	44
26	Pickaway County	93	65	28
27	Fairfield County	92	51	41
28	Darke County	88	58	30
29	Clark County	86	54	32
30	Greene County	86	60	26
31	Shelby County	86	65	21
32	Guernsey County	85	45	40
33	Auglaize County	83	56	27
34	Pike County	83	54	29
35	Muskingum County	82	28	54
36	Lorain County	81	17	62
37	Highland County	80	32	48
38	Erie County	78	36	26
39	Columbiana County	77	30	47
40	Monroe County	75	27	48
41	Stark County	74	25	49
42	Preble County	73	35	38
43	Trumbull County	72	31	41
44	Clinton County	71	44	27
45	Delaware County	70	52	18
46	Summit County	67	13	54
47	Miami County	66	43	23
48	Marion County	63	48	15
49	Perry County	63	21	42
50	Carroll County	61	19	42
51	Lucas County	59	22	22
52	Union County	59	44	15
53	Richland County	56	17	39
54	Jackson County	56	25	31
55	Harrison County	54	13	41
56	Ashland County	53	15	38
57	Ashtabula County	52	9	41
58	Hancock County	52	30	22
59	Lake County	51	23	26
60	Medina County	51	11	40
61	Fayette County	49	30	19
62	Sandusky County	49	27	12
63	Hardin County	48	32	16
64	Jefferson County	48	14	34
65	Champaign County	46	34	12
66	Morgan County	46	30	16
67	Ottawa County	44	9	14
68	Holmes County	43	14	29
69	Huron County	40	9	31
70	Crawford County	38	12	26
71	Mahoning County	37	19	18
72	Portage County	36	8	28
73	Wayne County	36	9	27
74	Wood County	36	21	15
75	Madison County	35	25	10
76	Wyandot County	33	13	20
77	Seneca County	32	9	23
78	Knox County	31	11	20
79	Geauga County	30	3	27
80	Morrow County	28	12	16
81	Paulding County	20	9	11
82	Putnam County	19	11	8
83	Henry County	18	8	10
84	Van Wert County	18	8	10
85	Defiance County	15	5	10
86	Fulton County	14	2	12
87	Allen County	13	4	9
88	Williams County	6	2	4

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

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