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Union County, Ohio

Natural disaster risk, federal disaster history and flood insurance facts.

Very Low overall risk
72nd of 88highest risk in Ohio
$19Mexpected losses a year
11federal declarations
1 in 333homes with flood insurance
Photo: U.S. Geological Survey, public domain

Union County, Ohio has a very low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 67% of US counties. It ranks 72nd of 88 counties in Ohio. The costliest hazards here are inland flooding, tornadoes and hail. FEMA estimates about $19 million a year in expected losses, or roughly $305 per resident. Since 1978 it has been included in 11 federal disaster or emergency declarations for natural events (6 major disasters). The most recent was in May 2024 (tornadoes). Fewer than 1 in 100 homes here carry federal flood insurance (58 policies). Since 1978, federal flood insurance has paid about $430,000 on 56 claims here.

FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.

Top risks in Union County

$12.9 million a yearExpected losses. Damaging events about 2 times a year.
  • Check the FEMA flood map for your address, and ask the seller or landlord about past flooding.
  • Price a flood policy now. Most new federal policies take 30 days to start.
$2.2 million a yearExpected losses. Damaging events about once every 4 years.
  • Pick a shelter spot: a basement, or an inside room on the lowest floor with no windows.
  • Turn on emergency alerts on your phone and keep a weather radio.

Hail

Low
$721,949 a yearExpected losses. Damaging events about 3 times a year.
  • Ask about the roof age and any impact-rated shingles.
  • Check your home policy for a separate wind and hail deductible.
HazardRatingScoreExpected loss a year
Inland floodingLow52.7
$13M
TornadoLow49.5
$2M
HailLow61.5
$722K
Heat waveLow49.2
$647K
Strong windLow32.7
$588K
Ice stormModerate75.0
$524K
Cold waveVery Low21.8
$467K
EarthquakeVery Low48.6
$459K
LightningLow36.6
$255K
Winter weatherLow58.3
$155K
DroughtLow35.5
$78K
HurricaneVery Low23.0
$14K
WildfireVery Low4.1
$2K
LandslideVery Low25.5
$364

Scores are percentiles: a score of 90 means higher risk than about 90% of US counties for that hazard. Hazards FEMA does not rate here are left out. Social vulnerability is very low and community resilience is very high in FEMA's measures.

Federal disaster history

Recent disasters nationwide ›

Declarations by decade

Federal declarations for natural events that included Union County. 2020s bar runs to November 2026.

By type

Severe Storm6
Snowstorm3
Hurricane1
Tornado1

Most recent

May 2, 2024TornadoesMajor disaster
Jun 30, 2012Severe StormsEmergency
Oct 24, 2008Severe Wind Storm Associated With Tropical Depression IkeMajor disaster
Apr 24, 2008Record Snow and Near Record SnowEmergency
Sep 13, 2005Hurricane Katrina EvacuationEmergency
Feb 15, 2005Severe Winter Storms, Flooding, and MudslidesMajor disaster
Jan 11, 2005SnowEmergency
Sep 19, 2004Severe Storms and FloodingMajor disaster
Mar 14, 2003Severe Winter Storm and Record/Near Record SnowMajor disaster
Nov 18, 2002Severe Storms and TornadoesMajor disaster
Show all 11
Jan 26, 1978Blizzards & SnowstormsEmergency

Ohio also had 3 statewide declarations that did not name single counties.

Storm history since 1963

Tornado risk by county ›

The National Weather Service has logged 274 storm reports in Union County since 1963, with 0 deaths and 11 injuries and about $5.6 million in reported damage. The strongest on record here was an F3 tornado on November 10, 2002 near Raymond.

12tornadoes
67hail reports, largest 2 inches
147damaging thunderstorm winds
46floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
Nov 10, 2002F3Raymond2 / 0
Mar 14, 2024EF2Lunda0 / 0
Apr 11, 1965F2–5 / 0
Jun 21, 1981F1–3 / 0
Nov 10, 2002F1York Center0 / 0

Most damaging storms

DateTypeNearDamage
Jun 1, 1997Flash FloodCountywide$3M
Nov 10, 2002TornadoRaymond$500K
Mar 14, 2024TornadoLunda$500K
Jun 21, 1981Tornado–$250K
Jun 13, 2022Thunderstorm WindMarysville$250K
Jun 6, 2010TornadoWest Marysville$64K

Source: NOAA Storm Events Database, county-based reports through Apr 14, 2026. Tornado records start in 1950, hail and wind in 1955, and floods and other storm types in 1996, so older decades undercount. Damage is in dollars of the year it happened and is often an estimate. Winter storms, heat and hurricanes are logged by forecast zone, not county, so they are not counted here.

Flood insurance in Union County

Check your address flood zone ›
0.3%of homes have federal flood insurance (58 policies)
15.5%of homes in mapped high-risk flood zones are insured
$429,718paid on 56 flood claims since 1978
1997costliest year, with $189,349 paid

National Flood Insurance Program (NFIP) records only; private flood policies are not included. Home counts as of Aug 3, 2026. Since 2021 NFIP prices each home separately under Risk Rating 2.0, so your price depends on the building, not the county. Ask an agent for a quote.

Homes in Union County

$344,900median home value (Ohio $214,800, US $332,700)
1996median year homes were built (Ohio 1970, US 1980)
36%of homes built before 1980, before many modern wind, quake and flood building rules
3.8%of homes are mobile homes, which are the least safe in tornadoes and high winds

Older homes and mobile homes usually suffer more damage in storms, floods and earthquakes, and can cost more to insure. If you are buying, ask about roof age, foundation bolting and any retrofits. Source: US Census Bureau, American Community Survey 2020 to 2024 5-year estimates; 25,158 housing units.

Compare in Ohio

All 88 ›
Largest countiesOverall riskTop hazard
Franklin CountyHighInland flooding
Cuyahoga CountyHighInland flooding
Hamilton CountyHighInland flooding
Summit CountyModerateInland flooding
Montgomery CountyModerateInland flooding
Lucas CountyModerateInland flooding
Butler CountyModerateInland flooding
Stark CountyModerateInland flooding

Neighboring counties

CountyOverall riskDeclarations
Franklin CountyHigh19
Delaware CountyLow13
Marion CountyLow10
Logan CountyLow12
Madison CountyVery Low10
Champaign CountyVery Low9
Hardin CountyVery Low10

Cities in Union County

Common questions about Union County

What is the biggest natural hazard in Union County?

Inland flooding has the highest expected yearly losses in Union County, about $12.9 million a year in FEMA's estimate. Tornado is second at $2.2 million.

How many federal disasters has Union County had?

Union County has been included in 11 federal disaster or emergency declarations for natural events since 1978, including 6 major disasters. The most recent was Tornadoes in May 2024.

Is Union County a high-risk place to live?

Its overall rating is Very Low, 72nd highest of 88 in Ohio. A county rating covers the whole area. Risk at one address can be much higher or lower, so check the FEMA flood map and ask about the home's history.

Do I need flood insurance in Union County?

Standard home insurance does not cover flooding. About 1 in 333 homes in Union County has federal flood insurance. Lenders require it in mapped high-risk zones, but many flood claims come from outside those zones.

How many tornadoes has Union County had?

NOAA records list 12 tornadoes in Union County since 1950. The strongest was an F3 tornado on November 10, 2002 near Raymond. The weather service has also logged 67 hail reports and 46 floods here.

Sources: FEMA National Risk Index (December 2025), OpenFEMA Disaster Declarations Summaries, and NFIP policy and claims data. Hazard Compass is independent and not affiliated with FEMA. These figures describe the whole county, not a single property, and are not insurance or safety advice. Report a problem.