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Knox County, Ohio Flood Zones

Check an Address in Knox County

Enter any address in Knox County, Ohio to see its FEMA flood zone

The Flooding Character of Knox County

Flash flooding from thunderstorms is the dominant flood character in Knox County. Recent events include flash flooding on June 5, 2024, associated with strong thunderstorms, and flash flooding on July 3, 2019, following multiple rounds of heavy rainfall.

National Flood Insurance Program (NFIP) data for Knox County shows a significant number of claims in Zone A, with an average payout of $2,628 and an average water depth of 1.4 feet. Claims in Zone X_UNSHADED also indicate potential flood risk, with an average payout of $2,862 and an average water depth of 2.9 feet, despite being designated as moderate flood risk. Homeowners in Zone A, Zone X_UNSHADED, and those in areas with unknown flood zone designations should pay particular attention to flood risk.

Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.

Read First-Hand Flood Stories from Knox County

13 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.

Read Ohio flood stories →

Flood Risk Data for Knox County

Knox County, Ohio has recorded 31 flood-related events since 1996 according to NOAA's Storm Events Database, including 20 flash floods and 11 river or area floods. The county has received 13 federal disaster declarations. Enter any address above to check its FEMA flood zone designation.

Knox County Disaster History

FEMA Disaster Declarations (1977–2020)

Disaster Declarations
13
Latest Disaster
Covid-19 Pandemic (2020-01-20)

Source: OpenFEMA Disaster Declarations Summaries.

Recent Disaster Declarations in Knox County

DeclarationTypeDate
Covid-19BiologicalJan 20, 2020
Covid-19 PandemicBiologicalJan 20, 2020
Severe StormsSevere StormJun 29, 2012
Severe Storms And Straight-line WindsSevere StormJun 29, 2012
Severe Wind Storm Associated With Tropical Depression IkeSevere StormSep 14, 2008
Hurricane Katrina EvacuationHurricaneAug 29, 2005
Severe Winter Storms, Flooding, And MudslidesSevere StormDec 22, 2004
Severe Storms And FloodingSevere StormAug 27, 2004
Severe Storms And FloodingSevere StormMay 18, 2004
Power OutageOtherAug 14, 2003

Recorded Flood Events in Knox County

NOAA Storm Events Database (1996–2025)

Total Flood Events
31
River/Area Floods
11
Flash Floods
20
Total Property Damage
$13.8M

Source: NOAA National Weather Service Storm Events Database.

Recent Flood Events in Knox County

TypeDateDamage
Flash FloodJun 5, 20240.00K
FloodMar 28, 20200.00K
FloodMay 18, 20200.00K
Flash FloodJul 3, 20192.00K
FloodFeb 15, 201825.00K
FloodApr 3, 20184.00K
FloodNov 18, 201750.00K
Flash FloodJun 13, 20170.00K
FloodJul 9, 20130.00K
FloodJul 8, 2013200.00K

Knox County Flood History

Flash Flood — Jun 5, 2024

Knox County resided in the warm and moist sector during the early through late evening of the 5th as a cold front swept eastward from northwestern IN and the Lower Ohio Valley to far-western OH and far-southeastern IN. Ahead of the cold front, scattered thunderstorms, including supercells, developed along a surface trough axis and resided in an environment favorable for tornadic supercells. Thi...

Flood — Mar 28, 2020

A warm front over central Ohio on the morning of Saturday March 28, 2020 was the focus for several rounds of elevated thunderstorms through the early afternoon hours. The main area for these thunderstorms were the US 30 and I-76 corridors through the morning and early afternoon hours as storms remained parallel to the warm front and moved with the 850 mb jet. These storms well utilized the stee...

Flood — May 18, 2020

A slow moving upper low over Illinois combined with a conveyor belt of humid air over Ohio supported widespread showers and thunderstorms over southern and central Ohio on the afternoon and evening of the 18th. The weather conditions supported not severe weather but heavy rain. Rain rates of 2 inches an hour or higher were observed with storms that trained, or repeated over the same areas. Ove...

Flash Flood — Jul 3, 2019

Multiple rounds of showers and thunderstorms moved across central Ohio in the afternoon and evening of July 2nd. By the early morning hours of July 3, a third round of showers moved along the US 30 corridor mainly over Marion, Morrow, Knox and counties further south. Rainfall of 1.5 to 2.5 inches across Marion, Morrow, and Knox Counties.

Flood — Feb 15, 2018

An active and warm weather pattern in February produced widespread minor flooding across the area. Starting during the second week of February a blocking pattern developed keeping a warm ridge of high pressure over the eastern U.S. with a flow from the Gulf of Mexico into the Ohio River Valley. The heaviest rains fell near and along a quasi-stationary front that lingered between northern Indian...

Source: NOAA National Weather Service Storm Events Database.

Knox County NFIP Flood Insurance Claims

Total Claims Filed
53
Total Paid Out
$169,737
Avg Claim
$4,849
Avg Water Depth
6.6 ft

Claims by Flood Zone

A Zones (High Risk)
30
X Shaded (500-yr)
3
X Unshaded (Low)
7

Source: OpenFEMA NFIP Individual Claims (2.25M records analyzed).

Flood Zone Types in Knox County

FEMA assigns flood zone designations to areas in Knox County, Ohio:

AE High Risk — 1% annual chance of flooding. Insurance required.

VE Very High Risk — Coastal flooding with wave action.

X (Shaded) Moderate Risk — 500-year floodplain.

X Low Risk — Outside major floodplains.

View all flood zone types →

Flood Insurance in Knox County

Properties in Knox County, Ohio that are in FEMA-designated Special Flood Hazard Areas (zones A and V) with federally backed mortgages are required to carry flood insurance.

Even outside high-risk zones, flood insurance is recommended. From 2014 to 2024, nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area.

Visit FloodSmart.gov to find an agent and get a quote.