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Marshall County, Iowa

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

Relatively Low overall risk
14th of 99highest risk in Iowa
$23Mexpected losses a year
18federal declarations
1 in 1000homes with flood insurance
Photo: U.S. Geological Survey, public domain

Marshall County, Iowa has a relatively low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is higher than 62% of US counties. It ranks 14th of 99 counties in Iowa. The costliest hazards here are inland flooding, tornadoes and drought. FEMA estimates about $23 million a year in expected losses, or roughly $565 per resident. Since 1965 it has been included in 18 federal disaster or emergency declarations for natural events (17 major disasters). The most recent was in May 2024 (severe storms, tornadoes and flooding). Only 27 homes here carry federal flood insurance. Since 1978, federal flood insurance has paid about $175,000 on 30 claims here.

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

Top risks in Marshall County

$9.9 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.

Tornado

Moderate
$4.5 million a yearExpected losses. Damaging events about once every 2 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.
$4.4 million a yearExpected losses. Damaging events about 7 times a year.
  • Check local water restrictions.
  • Choose drought-tolerant plants.
HazardRatingScoreExpected loss a year
Inland floodingLow63.1
$10M
TornadoModerate82.7
$4M
DroughtHigh97.9
$4M
Strong windHigh86.0
$2M
HailModerate80.9
$926K
Cold waveLow41.2
$685K
Winter weatherModerate84.7
$268K
WildfireVery Low62.1
$97K
LightningLow26.3
$93K
Ice stormLow50.1
$84K
EarthquakeVery Low27.5
$57K
Heat waveVery Low10.1
$18K
HurricaneVery Low15.2
$4K
LandslideVery Low51.0
$1K

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 relatively low and community resilience is relatively high in FEMA's measures.

Federal disaster history

Recent disasters nationwide ›

Declarations by decade

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

By type

Flood9
Severe Storm8
Hurricane1

Most recent

May 24, 2024Severe Storms, Tornadoes, and FloodingMajor disaster
Aug 17, 2020Severe StormsMajor disaster
Mar 23, 2019Severe Storms and FloodingMajor disaster
Sep 12, 2018Severe Storm and TornadoesMajor disaster
Jul 2, 2013Severe Storms, Tornadoes, and FloodingMajor disaster
Aug 24, 2011Severe Storms, Straight-Line Winds, and FloodingMajor disaster
May 27, 2008Severe Storms, Tornadoes, and FloodingMajor disaster
Mar 14, 2007Severe Winter StormsMajor disaster
Sep 10, 2005Hurricane Katrina EvacuationEmergency
May 25, 2004Severe Storms, Tornadoes, and FloodingMajor disaster
Show all 18
Jul 2, 1998Severe Storms, Tornadoes and FloodingMajor disaster
Jul 9, 1993Severe Storms & FloodingMajor disaster
Jul 12, 1991Severe Storms & FloodingMajor disaster
May 26, 1990Severe Storms & FloodingMajor disaster
Jun 24, 1974Severe Storms & FloodingMajor disaster
Aug 14, 1969Heavy Rains & FloodingMajor disaster
Apr 25, 1969FloodingMajor disaster
Apr 22, 1965FloodingMajor disaster

Iowa also had 11 statewide declarations that did not name single counties.

Storm history since 1951

Tornado risk by county ›

The National Weather Service has logged 509 storm reports in Marshall County since 1951, with 0 deaths and 50 injuries and about $516 million in reported damage. The strongest on record here was an F4 tornado on May 24, 1989.

38tornadoes
150hail reports, largest 3 inches
210damaging thunderstorm winds
57floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
May 24, 1989F4–0 / 0
Jul 19, 2018EF3Marietta23 / 0
Apr 23, 1961F3–6 / 0
Jun 1, 1951F3–7 / 0
Sep 16, 1978F3–0 / 0

Most damaging storms

DateTypeNearDamage
Jun 1, 2008FloodMinerva$250M
Jul 19, 2018TornadoMarietta$200M
May 24, 1989Tornado–$25M
Jun 12, 2010FloodSt Anthony$20M
Apr 23, 1961Tornado–$3M
Apr 10, 1981Tornado–$3M

Source: NOAA Storm Events Database, county-based reports through Sep 16, 2025. 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 Marshall County

Check your address flood zone ›
0.1%of homes have federal flood insurance (27 policies)
3.8%of homes in mapped high-risk flood zones are insured
$175,226paid on 30 flood claims since 1978
2014costliest year, with $107,585 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 Marshall County

$145,500median home value (Iowa $208,000, US $332,700)
1958median year homes were built (Iowa 1972, US 1980)
78%of homes built before 1980, before many modern wind, quake and flood building rules
2.7%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; 16,937 housing units.

Compare in Iowa

All 99 ›
Largest countiesOverall riskTop hazard
Polk CountyModerateInland flooding
Linn CountyModerateInland flooding
Scott CountyModerateInland flooding
Johnson CountyModerateTornado
Black Hawk CountyLowInland flooding
Woodbury CountyModerateInland flooding
Dallas CountyLowInland flooding
Dubuque CountyLowInland flooding

Neighboring counties

CountyOverall riskDeclarations
Story CountyLow20
Jasper CountyLow17
Poweshiek CountyVery Low13
Tama CountyLow19
Hardin CountyLow16
Grundy CountyVery Low13

Cities in Marshall County

Common questions about Marshall County

What is the biggest natural hazard in Marshall County?

Inland flooding has the highest expected yearly losses in Marshall County, about $9.9 million a year in FEMA's estimate. Tornado is second at $4.5 million.

How many federal disasters has Marshall County had?

Marshall County has been included in 18 federal disaster or emergency declarations for natural events since 1965, including 17 major disasters. The most recent was Severe Storms, Tornadoes, and Flooding in May 2024.

Is Marshall County a high-risk place to live?

Its overall rating is Relatively Low, 14th highest of 99 in Iowa. 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 Marshall County?

Standard home insurance does not cover flooding. About 1 in 1000 homes in Marshall 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 Marshall County had?

NOAA records list 38 tornadoes in Marshall County since 1950. The strongest was an F4 tornado on May 24, 1989. The weather service has also logged 150 hail reports and 57 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.