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Washington County, Iowa

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

Relatively Low overall risk
33rd of 99highest risk in Iowa
$14Mexpected losses a year
13federal declarations
1 in 111homes with flood insurance
Photo: U.S. Geological Survey, public domain

Washington County, Iowa has a relatively low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 56% of US counties. It ranks 33rd of 99 counties in Iowa. The costliest hazards here are inland flooding, strong wind and tornadoes. FEMA estimates about $14 million a year in expected losses, or roughly $616 per resident. Since 1965 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). Fewer than 1 in 100 homes here carry federal flood insurance (84 policies). Since 1978, federal flood insurance has paid about $189,000 on 15 claims here.

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

Top risks in Washington County

$6.2 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.
$2.1 million a yearExpected losses. Damaging events about 6 times a year.
  • Secure outdoor furniture and trash bins before storms.
  • Have trees near the house checked.
$1.6 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 floodingLow48.4
$6M
Strong windHigh90.9
$2M
TornadoLow57.0
$2M
HailModerate83.3
$1M
DroughtModerate79.0
$869K
Cold waveLow45.8
$800K
Heat waveLow64.7
$716K
LightningLow48.6
$220K
EarthquakeVery Low35.6
$114K
Ice stormLow47.0
$74K
Winter weatherLow53.1
$71K
WildfireVery Low54.9
$62K
HurricaneVery Low20.1
$6K
LandslideVery Low61.3
$3K

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 moderate 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 Washington County. 2020s bar runs to November 2026.

By type

Severe Storm7
Flood4
Hurricane1
Severe Ice Storm1

Most recent

Aug 17, 2020Severe StormsMajor disaster
Aug 5, 2014Severe Storms, Tornadoes, Straight-Line Winds, and FloodingMajor disaster
Jul 29, 2010Severe Storms, Flooding, and TornadoesMajor disaster
May 27, 2008Severe Storms, Tornadoes, and FloodingMajor disaster
Jan 4, 2008Severe Winter StormMajor disaster
Mar 14, 2007Severe Winter StormsMajor disaster
Sep 10, 2005Hurricane Katrina EvacuationEmergency
May 25, 2004Severe Storms, Tornadoes, and FloodingMajor disaster
Jul 2, 1998Severe Storms, Tornadoes and FloodingMajor disaster
Jun 24, 1996Severe Storms and FloodingMajor disaster
Show all 13
Jul 9, 1993Severe Storms & FloodingMajor disaster
May 26, 1990Severe Storms & FloodingMajor disaster
Apr 22, 1965FloodingMajor disaster

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

Storm history since 1964

Tornado risk by county ›

The National Weather Service has logged 372 storm reports in Washington County since 1964, with 0 deaths and 29 injuries and about $70.8 million in reported damage. The strongest on record here was an F3 tornado on May 15, 1998 near Washington.

27tornadoes
101hail reports, largest 2.75 inches
177damaging thunderstorm winds
57floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
May 15, 1998F3Washington28 / 0
Mar 31, 2023EF3West Chester0 / 0
May 8, 1988F2–0 / 0
Jun 7, 1984F2–0 / 0
May 8, 1988F2–0 / 0

Most damaging storms

DateTypeNearDamage
May 8, 1988Tornado–$25M
Jun 29, 1998Thunderstorm WindCountywide$21M
May 15, 1998TornadoWashington$9M
Jun 7, 1984Tornado–$3M
May 8, 1988Tornado–$3M
May 18, 2000HailWashington$2M

Source: NOAA Storm Events Database, county-based reports through Jul 20, 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 Washington County

Check your address flood zone ›
0.9%of homes have federal flood insurance (84 policies)
25.6%of homes in mapped high-risk flood zones are insured
$188,706paid on 15 flood claims since 1978
2013costliest year, with $86,729 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 Washington County

$203,900median home value (Iowa $208,000, US $332,700)
1964median year homes were built (Iowa 1972, US 1980)
66%of homes built before 1980, before many modern wind, quake and flood building rules
3.5%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; 9,657 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
Johnson CountyModerate22
Henry CountyVery Low14
Iowa CountyVery Low21
Jefferson CountyVery Low10
Louisa CountyVery Low18
Keokuk CountyVery Low17

Common questions about Washington County

What is the biggest natural hazard in Washington County?

Inland flooding has the highest expected yearly losses in Washington County, about $6.2 million a year in FEMA's estimate. Strong wind is second at $2.1 million.

How many federal disasters has Washington County had?

Washington County has been included in 13 federal disaster or emergency declarations for natural events since 1965, including 12 major disasters. The most recent was Severe Storms in August 2020.

Is Washington County a high-risk place to live?

Its overall rating is Relatively Low, 33rd 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 Washington County?

Standard home insurance does not cover flooding. About 1 in 111 homes in Washington 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 Washington County had?

NOAA records list 27 tornadoes in Washington County since 1950. The strongest was an F3 tornado on May 15, 1998 near Washington. The weather service has also logged 101 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.