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Ohio inland flooding risk

88 counties scored 0 rated Very High

Franklin County has the highest inland flooding risk in Ohio, scoring 98.8 out of 100 — rated "Relatively High" by FEMA's National Risk Index. Recorded inland flooding events across Ohio have decreased 30% over the past five years compared to the prior five-year period.

# County NRI score Rating NOAA events
2016–2026
1 Franklin County 98.8 Relatively High 82
2 Cuyahoga County 98.7 Relatively High 54
3 Hamilton County 96.9 Relatively High 112
4 Montgomery County 95.5 Relatively High 50
5 Lucas County 95.4 Relatively High 6
6 Summit County 94 Relatively High 21
7 Butler County 93 Relatively Moderate 50
8 Stark County 91.7 Relatively Moderate 14
9 Lorain County 90.2 Relatively Moderate 13
10 Trumbull County 88.8 Relatively Moderate 18
11 Mahoning County 88.1 Relatively Moderate 6
12 Belmont County 87 Relatively Moderate 47
13 Delaware County 86.4 Relatively Moderate 33
14 Lake County 86.1 Relatively Moderate 11
15 Licking County 86 Relatively Moderate 47
16 Clark County 84.2 Relatively Moderate 34
17 Warren County 83.9 Relatively Moderate 90
18 Muskingum County 83.8 Relatively Moderate 20
19 Athens County 83.7 Relatively Moderate 86
20 Lawrence County 83.7 Relatively Moderate 51
21 Allen County 83 Relatively Moderate 2
22 Tuscarawas County 82.3 Relatively Moderate 30
23 Columbiana County 82.2 Relatively Moderate 11
24 Scioto County 82 Relatively Moderate 72
25 Fairfield County 81.8 Relatively Moderate 51
26 Jefferson County 81.6 Relatively Moderate 10
27 Clermont County 81.3 Relatively Moderate 57
28 Washington County 80.5 Relatively Moderate 165
29 Wood County 75.7 Relatively Moderate 5
30 Medina County 75.5 Relatively Moderate 12
31 Greene County 75.4 Relatively Moderate 50
32 Portage County 75.3 Relatively Moderate 11
33 Brown County 75 Relatively Moderate 56
34 Ross County 74.5 Relatively Moderate 64
35 Geauga County 73.3 Relatively Moderate 4
36 Meigs County 72.7 Relatively Low 75
37 Ashtabula County 72.6 Relatively Low 7
38 Ottawa County 72.6 Relatively Low 8
39 Knox County 72 Relatively Low 8
40 Wayne County 71.9 Relatively Low 12
41 Erie County 71.8 Relatively Low 7
42 Richland County 71.6 Relatively Low 13
43 Holmes County 71.2 Relatively Low 5
44 Miami County 70.1 Relatively Low 9
45 Hocking County 68.8 Relatively Low 67
46 Logan County 67.7 Relatively Low 44
47 Sandusky County 67.7 Relatively Low 5
48 Gallia County 67.6 Relatively Low 53
49 Coshocton County 66.8 Relatively Low 23
50 Pickaway County 66 Relatively Low 48
51 Hancock County 65.4 Relatively Low 12
52 Marion County 64.9 Relatively Low 13
53 Adams County 64.3 Relatively Low 50
54 Pike County 63.9 Relatively Low 35
55 Shelby County 63.3 Relatively Low 33
56 Seneca County 61.2 Relatively Low 5
57 Huron County 60.5 Relatively Low 8
58 Ashland County 60.2 Relatively Low 14
59 Darke County 60.1 Relatively Low 21
60 Defiance County 59.4 Relatively Low 1
61 Guernsey County 58.9 Relatively Low 27
62 Jackson County 57.2 Relatively Low 25
63 Highland County 56.6 Relatively Low 36
64 Auglaize County 55.5 Relatively Low 24
65 Henry County 55.1 Relatively Low 1
66 Putnam County 52.8 Relatively Low 2
67 Union County 52.7 Relatively Low 26
68 Crawford County 51.9 Relatively Low 4
69 Williams County 51.8 Relatively Low 0
70 Preble County 51.4 Relatively Low 26
71 Monroe County 50.9 Relatively Low 27
72 Perry County 47 Relatively Low 35
73 Morgan County 45.3 Relatively Low 23
74 Morrow County 45 Relatively Low 7
75 Clinton County 44.7 Relatively Low 35
76 Champaign County 43.8 Relatively Low 18
77 Carroll County 42.8 Relatively Low 11
78 Fayette County 42.5 Relatively Low 23
79 Mercer County 42.1 Relatively Low 27
80 Fulton County 41.7 Relatively Low 2
81 Madison County 41.5 Relatively Low 12
82 Hardin County 40.2 Relatively Low 16
83 Paulding County 39.2 Relatively Low 1
84 Noble County 35.8 Relatively Low 49
85 Vinton County 34.6 Very Low 68
86 Van Wert County 33.7 Very Low 2
87 Wyandot County 30.5 Very Low 6
88 Harrison County 27.3 Very Low 13

Source: FEMA National Risk Index v1.20.0, December 2025. Scores are 0–100 percentile rankings among all US counties. See the methodology page for definitions. Download the full CSV for all counties.

Inland Flooding risk nationally:

Top 50 US counties

Other hazard risks in Ohio:

WildfireCoastal FloodingEarthquakeHeat WaveTornadoHurricaneHailStrong WindWinter WeatherIce StormCold WaveLightningDroughtLandslideAvalancheTsunamiVolcanic Activity

Frequently asked questions

What is the highest inland flooding risk county in Ohio?

Franklin County, OH has the highest inland flooding risk in Ohio, with a FEMA National Risk Index score of 98.8 out of 100 (rated "Relatively High").

What causes inland flooding risk in Ohio?

Inland flooding covers riverine and surface (pluvial) flooding — the most common and costly natural disaster type in the US. High scores appear across river floodplains in the Midwest, South, and Mid-Atlantic, where legacy development in flood-prone areas and aging stormwater infrastructure concentrate risk.