Home › Iowa › Grundy County

Grundy County, Iowa

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

Very Low overall risk
97th of 99highest risk in Iowa
$10Mexpected losses a year
13federal declarations
1 in 1000homes with flood insurance
Photo: U.S. Geological Survey, public domain

Grundy County, Iowa has a very low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 87% of US counties. It ranks 97th of 99 counties in Iowa. The costliest hazards here are inland flooding, drought and tornadoes. FEMA estimates about $9.5 million a year in expected losses, or roughly $772 per resident. Since 1969 it has been included in 13 federal disaster or emergency declarations for natural events (12 major disasters). The most recent was in August 2020 (severe storms). Only 3 homes here carry federal flood insurance. Since 1978, federal flood insurance has paid about $31,000 on 13 claims here.

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

Top risks in Grundy County

$3 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.

Drought

Moderate
$2.7 million a yearExpected losses. Damaging events about 13 times a year.
  • Check local water restrictions.
  • Choose drought-tolerant plants.
$1.1 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.
HazardRatingScoreExpected loss a year
Inland floodingVery Low14.2
$3M
DroughtModerate89.2
$3M
TornadoLow34.8
$1M
HailLow70.3
$956K
Strong windLow41.6
$739K
Cold waveLow30.3
$736K
Winter weatherLow57.4
$144K
Ice stormVery Low21.4
$31K
Heat waveVery Low9.4
$27K
LightningVery Low3.4
$20K
EarthquakeVery Low10.1
$17K
WildfireVery Low8.0
$4K
HurricaneVery Low9.3
$3K
LandslideVery Low11.9
$64

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 Grundy County. 2020s bar runs to November 2026.

By type

Severe Storm8
Flood4
Hurricane1

Most recent

Aug 17, 2020Severe StormsMajor disaster
Aug 5, 2014Severe Storms, Tornadoes, Straight-Line Winds, and FloodingMajor disaster
Jul 31, 2013Severe Storms, Tornadoes, and FloodingMajor disaster
Jul 2, 2013Severe Storms, Tornadoes, 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
May 2, 2001Severe Storms, Tornadoes and FloodingMajor disaster
Jul 2, 1998Severe Storms, Tornadoes and FloodingMajor disaster
Show all 13
Jul 9, 1993Severe Storms & FloodingMajor disaster
Jun 24, 1974Severe Storms & FloodingMajor disaster
Aug 14, 1969Heavy Rains & FloodingMajor disaster

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

Storm history since 1952

Tornado risk by county ›

The National Weather Service has logged 337 storm reports in Grundy County since 1952, with 1 death and 3 injuries and about $50.6 million in reported damage. The strongest on record here was an F4 tornado on May 30, 1989.

41tornadoes
91hail reports, largest 3 inches
120damaging thunderstorm winds
34floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
May 30, 1989F4–0 / 0
Apr 16, 1960F3–0 / 0
Jun 2, 1952F2–2 / 1
May 25, 2008EF2Fern0 / 0
Mar 22, 1991F2–0 / 0

Most damaging storms

DateTypeNearDamage
Jun 12, 2010FloodWellsburg$20M
Aug 9, 2009HailGrundy Center$15M
May 30, 1989Tornado–$3M
Jun 28, 1990Tornado–$3M
Aug 9, 2009HailWellsburg$1M
Jul 1, 2018FloodFredsville$600K

Source: NOAA Storm Events Database, county-based reports through Sep 22, 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 Grundy County

Check your address flood zone ›
0.1%of homes have federal flood insurance (3 policies)
20%of homes in mapped high-risk flood zones are insured
$31,395paid on 13 flood claims since 1978
2014costliest year, with $13,760 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 Grundy County

$198,800median home value (Iowa $208,000, US $332,700)
1962median year homes were built (Iowa 1972, US 1980)
75%of homes built before 1980, before many modern wind, quake and flood building rules
2.9%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; 5,498 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
Black Hawk CountyLow18
Marshall CountyLow18
Tama CountyLow19
Hardin CountyLow16
Butler CountyVery Low23
Franklin CountyVery Low20

Common questions about Grundy County

What is the biggest natural hazard in Grundy County?

Inland flooding has the highest expected yearly losses in Grundy County, about $3 million a year in FEMA's estimate. Drought is second at $2.7 million.

How many federal disasters has Grundy County had?

Grundy County has been included in 13 federal disaster or emergency declarations for natural events since 1969, including 12 major disasters. The most recent was Severe Storms in August 2020.

Is Grundy County a high-risk place to live?

Its overall rating is Very Low, 97th 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 Grundy County?

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

NOAA records list 41 tornadoes in Grundy County since 1950. The strongest was an F4 tornado on May 30, 1989. The weather service has also logged 91 hail reports and 34 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.