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Lyon County, Iowa

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

Very Low overall risk
86th of 99highest risk in Iowa
$11Mexpected losses a year
14federal declarations
1 in 143homes with flood insurance
Photo: U.S. Geological Survey, public domain

Lyon County, Iowa has a very low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 81% of US counties. It ranks 86th of 99 counties in Iowa. The costliest hazards here are inland flooding, hail and tornadoes. FEMA estimates about $11 million a year in expected losses, or roughly $913 per resident. Since 1965 it has been included in 14 federal disaster or emergency declarations for natural events (12 major disasters). The most recent was in June 2024 (severe storms, flooding, straight-line winds and tornadoes). Only 39 homes here carry federal flood insurance. Since 1978, federal flood insurance has paid about $1.7 million on 75 claims here, including $1.1 million for floods in 2014.

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

Top risks in Lyon County

$3.7 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.

Hail

Moderate
$2.5 million a yearExpected losses. Damaging events about 6 times a year.
  • Ask about the roof age and any impact-rated shingles.
  • Check your home policy for a separate wind and hail deductible.
$1.7 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 Low19.6
$4M
HailModerate89.4
$3M
TornadoLow45.9
$2M
Cold waveLow41.8
$1M
DroughtModerate72.0
$906K
Ice stormModerate67.9
$303K
Strong windLow18.6
$248K
Winter weatherModerate71.1
$209K
Heat waveVery Low29.9
$206K
LightningVery Low9.2
$47K
WildfireVery Low28.4
$20K
EarthquakeVery Low7.5
$11K
LandslideVery Low33.4
$615

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 relatively high in FEMA's measures.

Federal disaster history

Recent disasters nationwide ›

Declarations by decade

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

By type

Flood6
Severe Storm6
Drought1
Hurricane1

Most recent

Jun 24, 2024Severe Storms, Flooding, Straight-Line Winds, and TornadoesMajor disaster
Mar 23, 2019Severe Storms and FloodingMajor disaster
Aug 20, 2018Severe Storms, Tornadoes, Straight-Line Winds, and FloodingMajor disaster
Jul 24, 2014Severe Storms, Tornadoes, Straight-Line Winds, and FloodingMajor disaster
Jul 2, 2013Severe Storms, Tornadoes, and FloodingMajor disaster
May 6, 2013Severe Winter StormMajor disaster
Jul 29, 2010Severe Storms, Flooding, and TornadoesMajor disaster
May 27, 2008Severe Storms, Tornadoes, and FloodingMajor disaster
Sep 10, 2005Hurricane Katrina EvacuationEmergency
Jul 9, 1993Severe Storms & FloodingMajor disaster
Show all 14
Mar 31, 1977DroughtEmergency
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 446 storm reports in Lyon County since 1951, with 1 death and 2 injuries and about $38.1 million in reported damage. The strongest on record here was an F2 tornado on April 26, 1986.

43tornadoes
176hail reports, largest 4 inches
128damaging thunderstorm winds
97floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
Apr 26, 1986F2–2 / 1
Jul 6, 1978F2–0 / 0
Apr 26, 1986F2–0 / 0
May 7, 1993F2Larchwood0 / 0
Jun 25, 2010EF2Little Rock0 / 0

Most damaging storms

DateTypeNearDamage
Jun 20, 2024FloodBeloit$13M
Jun 12, 2001Flash FloodGeorge$4M
Jun 1, 2019FloodBeloit$4M
Jun 15, 2014FloodRock Rapids$3M
Apr 26, 1986Tornado–$3M
Jul 6, 1978Tornado–$3M

Source: NOAA Storm Events Database, county-based reports through Jul 25, 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 Lyon County

Check your address flood zone ›
0.7%of homes have federal flood insurance (39 policies)
0%of homes in mapped high-risk flood zones are insured
$1.7 millionpaid on 75 flood claims since 1978
2014costliest year, with $1.1 million 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 Lyon County

$230,000median home value (Iowa $208,000, US $332,700)
1967median year homes were built (Iowa 1972, US 1980)
65%of homes built before 1980, before many modern wind, quake and flood building rules
1.1%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; 4,870 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
Minnehaha County, SDModerate15
Lincoln County, SDLow15
Sioux CountyLow13
Nobles County, MNLow19
O'Brien CountyVery Low13
Rock County, MNVery Low14
Osceola CountyVery Low13

Common questions about Lyon County

What is the biggest natural hazard in Lyon County?

Inland flooding has the highest expected yearly losses in Lyon County, about $3.7 million a year in FEMA's estimate. Hail is second at $2.5 million.

How many federal disasters has Lyon County had?

Lyon County has been included in 14 federal disaster or emergency declarations for natural events since 1965, including 12 major disasters. The most recent was Severe Storms, Flooding, Straight-Line Winds, and Tornadoes in June 2024.

Is Lyon County a high-risk place to live?

Its overall rating is Very Low, 86th 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 Lyon County?

Standard home insurance does not cover flooding. About 1 in 143 homes in Lyon 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 Lyon County had?

NOAA records list 43 tornadoes in Lyon County since 1950. The strongest was an F2 tornado on April 26, 1986. The weather service has also logged 176 hail reports and 97 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.