County Hazards

States › South Dakota › Clay County

Clay County, South Dakota

Recorded hazard history: storm events since 1950, federal disaster declarations since 1953, flood insurance claims since 1978, and FEMA's risk index.

FIPS 46027 · 15,150 residents (2021) · 412 sq mi · dominant hazard Hail

Hail · 177Tornado · 31Flood · 67Wind · 160Winter · 159
1957-09-01: Hail1966-08-17: Hail1968-06-17: Hail1969-06-21: Hail1970-05-11: Hail1972-05-22: Hail1973-06-02: Hail1976-08-09: Hail1976-04-13: Hail1976-05-27: Hail1978-07-25: Hail1979-06-26: Hail1980-05-29: Hail1980-05-29: Hail1980-08-25: Hail1980-09-15: Hail1981-07-14: Hail1981-06-13: Hail1981-06-13: Hail1981-06-23: Hail1983-09-05: Hail1984-04-26: Hail1985-05-05: Hail1986-07-28: Hail1986-04-26: Hail1987-05-25: Hail1988-05-28: Hail1990-05-23: Hail1991-07-21: Hail1992-07-27: Hail1999-05-16: Hail1999-05-16: Hail2000-06-04: Hail2000-06-03: Hail2000-06-03: Hail2000-06-03: Hail2001-04-20: Hail2002-05-28: Hail2002-05-28: Hail2002-05-28: Hail2002-05-28: Hail2002-08-12: Hail2002-08-16: Hail2002-08-28: Hail2002-08-16: Hail2002-08-16: Hail2002-08-11: Hail2002-07-24: Hail2003-05-29: Hail2003-06-24: Hail2003-06-24: Hail2003-06-24: Hail2004-05-28: Hail2004-05-28: Hail2004-05-09: Hail2004-05-09: Hail2004-05-09: Hail2004-05-09: Hail2004-05-09: Hail2004-05-09: Hail2004-05-21: Hail2004-05-21: Hail2004-05-21: Hail2004-05-24: Hail2004-05-24: Hail2004-05-24: Hail2004-05-24: Hail2004-05-09: Hail2004-09-13: Hail2005-04-05: Hail2005-06-04: Hail2005-06-04: Hail2005-06-04: Hail2005-06-20: Hail2005-06-20: Hail2005-06-20: Hail2005-06-04: Hail2005-05-07: Hail2005-06-20: Hail2005-05-24: Hail2005-05-24: Hail2005-05-26: Hail2005-05-10: Hail2005-05-08: Hail2005-05-10: Hail2005-07-05: Hail2005-07-05: Hail2005-07-06: Hail2005-07-06: Hail2005-09-12: Hail2005-08-03: Hail2006-04-06: Hail2006-06-09: Hail2006-05-02: Hail2006-05-02: Hail2006-05-02: Hail2007-09-30: Hail2007-09-30: Hail2007-07-15: Hail2007-08-21: Hail2007-09-30: Hail2008-05-29: Hail2008-05-06: Hail2008-05-06: Hail2008-07-20: Hail2008-06-05: Hail2008-06-05: Hail2008-06-05: Hail2008-06-05: Hail2008-06-05: Hail2009-03-23: Hail2009-07-09: Hail2009-07-09: Hail2009-07-09: Hail2009-07-09: Hail2009-07-09: Hail2009-06-16: Hail2009-06-16: Hail2009-06-16: Hail2009-06-17: Hail1965-06-07: Tornado1965-06-07: Tornado1966-05-22: Tornado1967-08-16: Tornado1968-06-13: Tornado1970-06-15: Tornado1980-05-29: Tornado1981-09-26: Tornado1981-06-23: Tornado1984-06-11: Tornado1985-08-12: Tornado1985-04-20: Tornado1986-07-28: Tornado1986-06-21: Tornado1988-05-20: Tornado1990-06-16: Tornado1992-06-16: Tornado2000-06-03: Tornado2003-06-24: Tornado2003-06-24: Tornado2003-06-24: Tornado2003-06-24: Tornado2003-06-24: Tornado2003-06-24: Tornado2003-06-24: Tornado2003-06-24: Tornado2004-05-29: Tornado2008-05-29: Tornado2008-05-29: Tornado2021-05-15: Tornado2005-04-21: Flood2005-06-20: Flood2005-06-04: Flood2005-05-31: Flood2007-05-05: Flood2007-04-04: Flood2007-03-11: Flood2008-06-04: Flood2009-07-07: Flood2009-07-10: Flood2009-07-09: Flood2010-06-12: Flood2010-06-11: Flood2010-09-27: Flood2010-06-22: Flood2010-07-24: Flood2010-08-01: Flood2010-03-13: Flood2010-07-21: Flood2011-03-16: Flood2011-04-01: Flood2011-05-25: Flood2011-07-01: Flood2011-06-01: Flood2011-06-26: Flood2011-08-01: Flood2012-05-11: Flood2013-05-27: Flood2014-06-17: Flood2014-06-16: Flood2014-06-15: Flood2016-04-28: Flood2016-09-07: Flood2018-03-27: Flood2018-06-21: Flood2018-06-26: Flood2018-09-22: Flood2019-06-01: Flood2019-06-01: Flood2019-05-25: Flood2019-06-01: Flood2019-03-13: Flood2019-05-30: Flood2019-03-14: Flood2019-03-15: Flood2019-09-12: Flood2019-03-13: Flood2019-05-11: Flood2019-09-18: Flood2019-09-13: Flood2019-04-09: Flood2020-04-01: Flood2020-07-28: Flood2020-07-28: Flood2020-03-07: Flood2024-06-21: Flood2024-06-21: Flood2024-06-21: Flood2024-06-23: Flood1955-09-20: Wind1959-05-02: Wind1964-06-22: Wind1971-06-06: Wind1974-06-21: Wind1974-04-11: Wind1978-07-06: Wind1978-06-25: Wind1980-06-07: Wind1981-07-14: Wind1981-07-14: Wind1982-08-31: Wind1982-09-28: Wind1982-07-20: Wind1983-07-22: Wind1983-07-22: Wind1983-07-22: Wind1983-07-18: Wind1984-06-11: Wind1984-07-16: Wind1985-08-12: Wind1986-08-16: Wind1986-07-10: Wind1986-06-21: Wind1987-07-11: Wind1988-05-29: Wind1992-07-22: Wind1992-08-09: Wind1992-08-09: Wind1992-08-09: Wind1992-06-15: Wind1992-09-14: Wind1997-07-27: Wind1998-07-06: Wind1998-07-21: Wind1999-06-27: Wind1999-06-27: Wind1999-06-27: Wind2000-02-25: Wind2000-05-07: Wind2000-06-04: Wind2000-08-05: Wind2000-06-03: Wind2000-06-03: Wind2000-07-11: Wind2002-07-25: Wind2002-06-17: Wind2003-07-03: Wind2003-07-03: Wind2005-06-20: Wind2005-05-26: Wind2006-05-23: Wind2006-05-23: Wind2006-05-23: Wind2007-07-15: Wind2008-05-29: Wind2008-05-29: Wind2008-05-29: Wind2008-05-06: Wind2008-05-06: Wind2008-05-29: Wind2009-06-16: Wind2009-06-16: Wind2009-06-16: Wind2009-06-16: Wind2009-06-16: Wind2009-06-17: Wind2010-06-26: Wind2010-06-11: Wind2010-06-11: Wind2010-06-11: Wind2010-06-11: Wind2010-06-11: Wind2010-06-11: Wind2010-05-24: Wind2010-05-24: Wind2010-06-11: Wind2011-05-11: Wind2013-07-07: Wind2013-07-07: Wind2014-06-01: Wind2015-08-09: Wind2015-08-09: Wind2016-05-25: Wind2017-06-13: Wind2018-08-05: Wind2019-07-17: Wind2019-07-17: Wind2020-05-24: Wind2020-07-03: Wind2020-07-28: Wind2020-07-28: Wind2021-06-11: Wind2021-09-16: Wind2022-05-12: Wind
Clay County within South Dakota. Dots: HailTornadoFloodWind event locations in the kept record. Boundaries: US Census Bureau.

NCEI notes that Storm Data is compiled from a variety of sources including the National Weather Service, other federal, state and local agencies, the media and the public; that property and crop damage figures are estimates; and that some events are recorded by NWS forecast zone rather than by county. FEMA notes that NFIP claim records are redacted and aggregated to protect the privacy of policyholders. NCEI storm records through 30 Jun 2026; OpenFEMA declarations refreshed 1 Oct 2026; NFIP claims as of 8 Sep 2026.

Between 1950 and 2026, NCEI recorded 708 storm events in Clay County, South Dakota, led by hail.

That is 171.8 events per 100 square miles, above the South Dakota figure of 73.7, and 467.3 per 10,000 residents against 624.1 statewide.

31 events fall in the 12 months to 30 Jun 2026. NCEI attributes 0 deaths and 3 injuries to events in the county, with property damage estimated at $11M and crop damage at $65M.

FEMA has designated the county in 19 federal disaster declarations since 1953; the most recent is Severe Storms, Straight-Line Winds, And Flooding (major disaster, 15 Aug 2024).

National Flood Insurance Program policyholders in the county filed 13 claims since 1978, of which 9 were paid, totalling $53K (about $6K per paid claim). FEMA counts 6 residential flood policies in force.

FEMA's National Risk Index rates the county's overall risk as "Very Low" and its expected annual loss as "Very Low" ($12M a year across 18 hazards).

31events, last 12 monthsto 30 Jun 2026
708events since 19500 deaths, 3 injuries recorded
19disaster declarationslast 15 Aug 2024
13NFIP flood claims$53K paid

Compared with South Dakota and the United States

MeasureClay CountySouth DakotaUS
Recorded events since 195070855,8771,977,440
Events per 100 square miles171.873.756.0
Events per 10,000 residents467.3624.159.6
Events in the last 12 months312,30362,008
Deaths recorded by NCEI014726,435
Property damage (NCEI estimates)$11M$1.1B$575B
NFIP claims per 1,000 residents0.94.58.1
Average paid NFIP claim$6K$21K$43K
Claims per 100 policies in force, last 10 years16.730.716.1

County-recorded events plus zone-recorded events whose forecast zone is named for the county. State and US rows include events recorded only by forecast zone. Rates use 2021 Census population and land area.

Events by decade

Hail: 1Wind: 2
Hail: 3Tornado: 6Wind: 1
Hail: 8Tornado: 1Wind: 5
Hail: 15Tornado: 9Wind: 18
Hail: 5Tornado: 2Flood: 3Wind: 19Winter: 11Cold: 2Drought: 2Lightning: 1
Hail: 90Tornado: 12Flood: 16Wind: 38Winter: 45Drought: 5
Hail: 31Flood: 40Wind: 28Winter: 60Heat: 13Cold: 9Drought: 12Other: 1
Hail: 24Tornado: 1Flood: 8Wind: 49Winter: 43Heat: 15Cold: 16Drought: 38
31950s101960s141970s421980s451990s2062000s1942010s1942020s
Recorded events in Clay County by decade and hazard group. HailTornadoFloodWindWinterHeatColdDroughtLightningOther NCEI recorded only tornadoes, hail and thunderstorm wind before 1996.

Trend: 457 events in the 20 years to 2025 against 179 in the 20 years before. Reporting practice changed in 1996 and again with automated reports in the 2000s, so decade totals measure the record as much as the weather.

Events by type

Hail177
Wind160
Winter159
Flood67
Drought57
Tornado31
Heat28
Cold27
Lightning1
Other1
HazardEventsDeathsShare of state's events
■ Hail177—1.0%detail
■ Wind160—0.9%detail
■ Winter159—1.6%detail
■ Flood67—2.0%detail
■ Drought57—2.8%
■ Tornado31—1.6%detail
■ Heat28—3.2%
■ Cold27—1.4%
■ Lightning1—0.8%
■ Other1—0.4%

Hazard pages exist for hail, tornado, flood, wind and winter where the county has at least 10 recorded events. "Other" covers heavy rain, debris flow, dust, funnel clouds and similar reports.

Largest recorded events

DateEvent typeGroupMagnitudeProperty damageCrop damageDeathsInjuriesGeography
1 Jun 2019FloodFlood——$26M——County
1 Jul 2022DroughtDrought——$25M——Forecast zone
21 Jul 1998Thunderstorm WindWind66 mph———2County
28 Nov 2018Winter WeatherWinter————1Forecast zone
21 Jun 2024FloodFlood—$6.5M———County
1 Aug 2022DroughtDrought——$4.3M——Forecast zone
16 Jun 1990TornadoTornadoF1$2.5M———County
1 Jul 2023DroughtDrought——$2.0M——Forecast zone
1 Sep 2022DroughtDrought——$1.9M——Forecast zone
1 Jun 2022DroughtDrought——$1.6M——Forecast zone
1 Jul 2021DroughtDrought——$1.2M——Forecast zone
1 Aug 2021DroughtDrought——$686K——Forecast zone
1 Jun 2021DroughtDrought——$495K——Forecast zone
15 Sep 2020DroughtDrought——$450K——Forecast zone
13 Mar 2019FloodFlood—$440K———County
27 Jul 1997Thunderstorm WindWind70 mph$200K$50K——County
22 Sep 2010HailHail3.00 in$250K———County
1 Apr 2001FloodFlood—$200K———Forecast zone
1 Sep 2021DroughtDrought——$191K——Forecast zone
1 May 2022DroughtDrought——$162K——Forecast zone

Ranked by deaths, then injuries, then NCEI's damage estimate. Deaths and injuries are NCEI counts (direct plus indirect); no personal details are recorded here.

Federal disaster declarations

DeclaredNumberTypeIncidentTitlePrograms
15 Aug 2024DR-4807Major disasterFloodSevere Storms, Straight-Line Winds, And FloodingPublic assistance
29 Jun 2022DR-4656Major disasterSevere StormSevere Storm, Straight-Line Winds, Tornadoes, And FloodingPublic assistance
5 Apr 2020DR-4527Major disasterBiologicalCovid-19 PandemicIndividual assistance, Public assistance
13 Mar 2020EM-3475EmergencyBiologicalCovid-19Public assistance
7 Jun 2019DR-4440Major disasterFloodSevere Winter Storm, Snowstorm, And FloodingPublic assistance
28 Jul 2014DR-4186Major disasterFloodSevere Storms, Tornadoes, And FloodingPublic assistance
13 May 2011DR-1984Major disasterFloodFloodingPublic assistance
23 Sep 2010DR-1938Major disasterSevere StormSevere Storms And FloodingPublic assistance
13 May 2010DR-1915Major disasterFloodFloodingPublic assistance
9 Mar 2010DR-1886Major disasterSevere StormSevere Winter Storm And SnowstormPublic assistance
9 Jul 2008DR-1774Major disasterSevere StormSevere Storms And FloodingPublic assistance
10 Sep 2005EM-3234EmergencyCoastal StormHurricane Katrina EvacuationPublic assistance
7 Apr 1997DR-1173Major disasterFloodSevere Flooding, Sever Winter Storms,Heavy Rains High WindsIndividual assistance, Public assistance
10 Jan 1997DR-1156Major disasterSevere StormSevere Winter Storms And Blizzard ConditionsPublic assistance
26 May 1995DR-1052Major disasterFloodFloodingIndividual assistance, Public assistance
19 Jul 1993DR-999Major disasterSevere StormSevere Storms, Tornadoes & FloodingIndividual assistance, Public assistance
19 Jul 1984DR-717Major disasterFloodSevere Storms & FloodingPublic assistance
17 Jun 1976EM-3015EmergencyDroughtDroughtPublic assistance
18 Apr 1969DR-257Major disasterFloodFloodingIndividual assistance, Public assistance

Declarations in which FEMA designated this county, from the OpenFEMA Disaster Declarations Summaries (v2). DR: major disaster; EM: emergency; FM: fire management assistance. Programs show whether individual or public assistance was made available.

Flood insurance claims

197820022026
NFIP claims by year of loss in Clay County, 1978 to 2026 (hover for the amount paid).
Claims since 197813
Paid claims9
Total paid$53K
Average paid claim$6K
Repetitive-loss properties10 severe
Residential policies in force60.1% of 6,253 structures
Year of lossClaimsPaid claimsAmount paidAverage paid
202411$2,000$2,000
2011106$46,072$7,679
199911$3,185$3,185
199711$1,696$1,696

OpenFEMA NFIP claims (v3, as of 8 Sep 2026), aggregated by year of loss; amounts are building, contents and increased-cost-of-compliance payments as recorded. Repetitive-loss counts from the NFIP Multiple Loss Properties file (2 Aug 2026); policies in force from the NFIP Residential Penetration Rates file (3 Aug 2026).

National Risk Index

Overall riskVery Lowscore 20.5 of 100
Expected annual loss$12MVery Low
Social vulnerabilityVery Low
Community resilienceVery High
Hazard (NRI)Risk ratingExpected annual loss
Inland floodingVery Low$5,301,469
TornadoRelatively Low$2,796,643
DroughtRelatively Moderate$954,660
HailRelatively Low$715,034
Strong windRelatively Low$488,363
Cold waveVery Low$434,263
Ice stormRelatively Moderate$231,314
Winter weatherRelatively Moderate$223,683
LightningRelatively Low$217,711
Heat waveVery Low$214,662
WildfireVery Low$45,957
EarthquakeVery Low$21,498
LandslideVery Low$570

FEMA National Risk Index, December 2025 release. Ratings are FEMA's relative comparison of counties; expected annual loss is FEMA's modelled estimate of average yearly building, population and agriculture loss. See how to read the NRI.

Hurricane and tropical storm passes

No HURDAT2 track at tropical-storm strength passes within 100 miles of the county's centre point (through the 2025 season).

ZIP codes with flood claims

ZIP codes whose NFIP claims carry this county's code, with the number of claims. Five or more claims are needed for a ZIP page to be indexed.

Questions and answers

How often does it hail in Clay County, SD?

NCEI records 177 hail events in Clay County since 1950, in 47 different years; that is about 2.3 recorded events a year. 30 reports were golf-ball size (1.75 in) or larger.

Has Clay County had a tornado?

Yes. NCEI records 31 tornadoes in Clay County since 1950, 6 of them rated (E)F2 or stronger. Tornado deaths recorded: 0.

When was the last federal disaster declaration for Clay County?

15 Aug 2024: Severe Storms, Straight-Line Winds, And Flooding, a major disaster declaration for flood. The county appears in 19 declarations since 1953.

How many flood insurance claims have been filed in Clay County, and how much was paid?

13 NFIP claims since 1978, 9 of them paid, for $53K in total. FEMA publishes these figures redacted and aggregated; individual properties are not identified.

Is Clay County in the National Risk Index's high-risk band?

FEMA's National Risk Index (December 2025) rates the county "Very Low" for overall risk, "Very Low" for expected annual loss, "Very Low" for social vulnerability and "Very High" for community resilience. These ratings are FEMA's relative comparison across all US counties.

How does Clay County compare with the rest of South Dakota?

171.8 recorded events per 100 square miles against 73.7 statewide, and 0.9 NFIP claims per 1,000 residents against 4.5. The comparison table on this page shows each measure beside the state and national figures.

Provenance

Storm events: NOAA NCEI Storm Events Database, yearly details files through 30 Jun 2026 (public domain). Declarations: OpenFEMA DisasterDeclarationsSummaries v2, refreshed 1 Oct 2026. Flood claims: OpenFEMA NfipClaims v3 as of 8 Sep 2026; NfipMultipleLossProperties v1 (2 Aug 2026); NfipResidentialPenetrationRates v1 (3 Aug 2026). Risk index: FEMA National Risk Index, December 2025. Hurricane tracks: NHC HURDAT2 through 2025. Population and area: US Census Bureau, 2021 vintage. Built 1 Oct 2026; see the methodology and corrections pages. Hazard hubs: Hail · Tornado · Flood · Wind · Winter.