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Corson County, South Dakota

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

Very Low overall risk
19th of 66highest risk in South Dakota
$7Mexpected losses a year
14federal declarations
Photo: Bold Frontiers, CC BY 2.0

Corson County, South Dakota has a very low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 62% of US counties. It ranks 19th of 66 counties in South Dakota. The costliest hazards here are cold waves, inland flooding and hail. FEMA estimates about $7.1 million a year in expected losses, or roughly $1,821 per resident. Since 1976 it has been included in 14 federal disaster or emergency declarations for natural events (12 major disasters). The most recent was in July 2014 (severe storms, tornadoes and flooding). Only 1 home here carries federal flood insurance.

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

Top risks in Corson County

$4.9 million a yearExpected losses. Damaging events about 10 times a year.
  • Insulate pipes in outside walls, crawl spaces and garages.
  • Know how to shut off the main water valve.
$1.1 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

Low
$267,938 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
Cold waveHigh91.8
$5M
Inland floodingVery Low16.1
$1M
HailLow64.8
$268K
Strong windLow35.7
$213K
TornadoVery Low23.6
$194K
WildfireLow77.3
$188K
Winter weatherModerate77.1
$108K
LightningVery Low14.8
$30K
Heat waveVery Low17.8
$30K
Ice stormLow37.4
$28K
DroughtVery Low28.5
$12K
EarthquakeVery Low7.4
$4K
LandslideVery Low21.6
$82

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

Federal disaster history

Recent disasters nationwide ›

Declarations by decade

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

By type

Severe Storm8
Snowstorm2
Flood2
Drought1
Coastal Storm1

Most recent

Jul 28, 2014Severe Storms, Tornadoes, and FloodingMajor disaster
Nov 8, 2013Severe Winter Storm, Snowstorm, and FloodingMajor disaster
Jun 28, 2013Severe Storms, Tornado, and FloodingMajor disaster
May 13, 2010Severe Winter StormMajor disaster
Mar 10, 2010Severe Winter StormMajor disaster
Jun 16, 2009Severe Storms and FloodingMajor disaster
Dec 12, 2008Severe Winter Storm and Record and Near Record SnowMajor disaster
Sep 10, 2005Hurricane Katrina EvacuationEmergency
Jul 22, 2005Severe StormMajor disaster
Apr 7, 1997Severe Flooding, Sever Winter Storms,Heavy Rains High WindsMajor disaster
Show all 14
Jan 10, 1997Severe Winter Storms and Blizzard ConditionsMajor disaster
Mar 14, 1995Severe Winter StormsMajor disaster
Jul 19, 1993Severe Storms, Tornadoes & FloodingMajor disaster
Jun 17, 1976DroughtEmergency

South Dakota also had 46 statewide declarations that did not name single counties.

Storm history since 1953

Tornado risk by county ›

The National Weather Service has logged 629 storm reports in Corson County since 1953, with 0 deaths and 4 injuries and about $2 million in reported damage. The strongest on record here was an F2 tornado on May 29, 1953.

23tornadoes
311hail reports, largest 3 inches
241damaging thunderstorm winds
50floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
May 29, 1953F2–2 / 0
Apr 19, 1955F0–2 / 0
Apr 19, 1955F0–0 / 0
Jun 21, 1983F0–0 / 0
Jul 24, 1966F0–0 / 0

Most damaging storms

DateTypeNearDamage
Jun 1, 2019FloodThunder Hawk$2M
May 29, 1953Tornado–$250K
Jul 4, 1994Thunderstorm WindMclaughlin$100K
Jul 4, 1994HailPerkins And$100K
Mar 20, 2009FloodWakpala$50K
Aug 13, 1993Thunderstorm Wind–$5K

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 Corson County

Check your address flood zone ›
0%of homes have federal flood insurance (1 policies)
0%of homes in mapped high-risk flood zones are insured
$450paid on 1 flood claims since 1978
1978costliest year, with $450 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 Corson County

$69,800median home value (South Dakota $257,400, US $332,700)
1974median year homes were built (South Dakota 1980, US 1980)
60%of homes built before 1980, before many modern wind, quake and flood building rules
11.8%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; 1,359 housing units.

Compare in South Dakota

All 66 ›
Largest countiesOverall riskTop hazard
Minnehaha CountyModerateTornado
Pennington CountyLowInland flooding
Lincoln CountyLowTornado
Brown CountyLowCold wave
Brookings CountyLowInland flooding
Meade CountyLowInland flooding
Codington CountyLowInland flooding
Lawrence CountyLowInland flooding

Neighboring counties

CountyOverall riskDeclarations
Walworth CountyVery Low10
Dewey CountyLow14
Sioux County, NDLow20
Emmons County, NDLow24
Perkins CountyVery Low19
Ziebach CountyVery Low19
Adams County, NDVery Low13
Campbell CountyVery Low13

Common questions about Corson County

What is the biggest natural hazard in Corson County?

Cold wave has the highest expected yearly losses in Corson County, about $4.9 million a year in FEMA's estimate. Inland flooding is second at $1.1 million.

How many federal disasters has Corson County had?

Corson County has been included in 14 federal disaster or emergency declarations for natural events since 1976, including 12 major disasters. The most recent was Severe Storms, Tornadoes, and Flooding in July 2014.

Is Corson County a high-risk place to live?

Its overall rating is Very Low, 19th highest of 66 in South Dakota. 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 Corson County?

Standard home insurance does not cover flooding. Lenders require it in mapped high-risk zones, but many flood claims come from outside those zones.

How many tornadoes has Corson County had?

NOAA records list 23 tornadoes in Corson County since 1950. The strongest was an F2 tornado on May 29, 1953. The weather service has also logged 311 hail reports and 50 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.