States › South Dakota › Day County
Day 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.
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.
The NCEI record lists 747 events for Day County, South Dakota, between 1950 and 2026; damaging wind account for the largest share.
That is 72.6 events per 100 square miles, in line with the South Dakota figure of 73.7, and 1,379.8 per 10,000 residents against 624.1 statewide.
37 events fall in the 12 months to 30 Jun 2026. NCEI attributes 1 death and 16 injuries to events in the county, with property damage estimated at $5.7M and crop damage at $20M.
FEMA has designated the county in 25 federal disaster declarations since 1953; the most recent is Severe Storms, Straight-Line Winds, Tornadoes, And Flooding (major disaster, 1 Sep 2026).
National Flood Insurance Program policyholders in the county filed 257 claims since 1978, of which 198 were paid, totalling $4.2M (about $21K per paid claim). FEMA counts 12 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" ($7.2M a year across 18 hazards).
Compared with South Dakota and the United States
| Measure | Day County | South Dakota | US |
|---|---|---|---|
| Recorded events since 1950 | 747 | 55,877 | 1,977,440 |
| Events per 100 square miles | 72.6 | 73.7 | 56.0 |
| Events per 10,000 residents | 1,379.8 | 624.1 | 59.6 |
| Events in the last 12 months | 37 | 2,303 | 62,008 |
| Deaths recorded by NCEI | 1 | 147 | 26,435 |
| Property damage (NCEI estimates) | $5.7M | $1.1B | $575B |
| NFIP claims per 1,000 residents | 47.5 | 4.5 | 8.1 |
| Average paid NFIP claim | $21K | $21K | $43K |
| Claims per 100 policies in force, last 10 years | 41.7 | 30.7 | 16.1 |
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
Trend: 471 events in the 20 years to 2025 against 222 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
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
| Date | Event type | Group | Magnitude | Property damage | Crop damage | Deaths | Injuries | Geography |
|---|---|---|---|---|---|---|---|---|
| 23 Dec 2020 | Blizzard | Winter | — | — | — | 1 | — | Forecast zone |
| 31 Jul 2008 | Thunderstorm Wind | Wind | 120 mph | — | — | — | 10 | County |
| 23 Jul 2005 | Thunderstorm Wind | Wind | 81 mph | — | — | — | 4 | County |
| 1 Jun 2019 | Flood | Flood | — | — | $12M | — | — | County |
| 25 Jun 1973 | Tornado | Tornado | F1 | $3K | — | — | 1 | County |
| 2 Dec 2011 | Strong Wind | Wind | 49 mph | — | — | — | 1 | Forecast zone |
| 1 Jul 2005 | Flood | Flood | — | $130K | $7.5M | — | — | Forecast zone |
| 19 Jun 1979 | Tornado | Tornado | F1 | $2.5M | — | — | — | County |
| 11 May 1998 | Flood | Flood | — | $1.9M | — | — | — | Forecast zone |
| 25 Dec 2016 | Ice Storm | Winter | — | $665K | — | — | — | Forecast zone |
| 24 Jun 1994 | Hail | Hail | 1.75 in | $50K | $500K | — | — | County |
| 12 Apr 2023 | Flood | Flood | — | $150K | $150K | — | — | County |
| 17 Jul 1996 | Tornado | Tornado | F2 | $200K | — | — | — | County |
| 1 Apr 2019 | Flood | Flood | — | $104K | — | — | — | County |
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
| Declared | Number | Type | Incident | Title | Programs |
|---|---|---|---|---|---|
| 1 Sep 2026 | DR-4938 | Major disaster | Severe Storm | Severe Storms, Straight-Line Winds, Tornadoes, And Flooding | Public assistance |
| 6 Jul 2023 | DR-4718 | Major disaster | Flood | Flooding | Public assistance |
| 27 Feb 2023 | DR-4689 | Major disaster | Winter Storm | Severe Winter Storms And Snowstorm | Public assistance |
| 29 Jun 2022 | DR-4656 | Major disaster | Severe Storm | Severe Storm, Straight-Line Winds, Tornadoes, And Flooding | Public assistance |
| 5 Apr 2020 | DR-4527 | Major disaster | Biological | Covid-19 Pandemic | Individual assistance, Public assistance |
| 13 Mar 2020 | EM-3475 | Emergency | Biological | Covid-19 | Public assistance |
| 18 Nov 2019 | DR-4469 | Major disaster | Severe Storm | Severe Storms, Tornadoes, And Flooding | Public assistance |
| 7 Jun 2019 | DR-4440 | Major disaster | Flood | Severe Winter Storm, Snowstorm, And Flooding | Public assistance |
| 1 Feb 2017 | DR-4298 | Major disaster | Severe Storm | Severe Winter Storm | Public assistance |
| 13 May 2011 | DR-1984 | Major disaster | Flood | Flooding | Public assistance |
| 13 May 2010 | DR-1915 | Major disaster | Flood | Flooding | Public assistance |
| 10 Mar 2010 | DR-1887 | Major disaster | Severe Storm | Severe Winter Storm | Public assistance |
| 16 Jun 2009 | DR-1844 | Major disaster | Severe Storm | Severe Storms And Flooding | Public assistance |
| 22 May 2007 | DR-1702 | Major disaster | Severe Storm | Severe Storms, Tornadoes, And Flooding | Public assistance |
| 20 Dec 2005 | DR-1620 | Major disaster | Severe Storm | Severe Winter Storm | Public assistance |
| 10 Sep 2005 | EM-3234 | Emergency | Coastal Storm | Hurricane Katrina Evacuation | Public assistance |
| 17 May 2001 | DR-1375 | Major disaster | Flood | Severe Winter Storms, Flooding, And Ice Jams | Public assistance |
| 1 Jun 1998 | DR-1218 | Major disaster | Flood | Flooding, Severe Storms, Tornadoes | Individual assistance, Public assistance |
| 7 Apr 1997 | DR-1173 | Major disaster | Flood | Severe Flooding, Sever Winter Storms,Heavy Rains High Winds | Individual assistance, Public assistance |
| 10 Jan 1997 | DR-1156 | Major disaster | Severe Storm | Severe Winter Storms And Blizzard Conditions | Public assistance |
| 26 May 1995 | DR-1052 | Major disaster | Flood | Flooding | Individual assistance, Public assistance |
| 21 Jun 1994 | DR-1031 | Major disaster | Severe Storm | Severe Storms And Flooding | Public assistance |
| 19 Jul 1993 | DR-999 | Major disaster | Severe Storm | Severe Storms, Tornadoes & Flooding | Individual assistance, Public assistance |
| 3 May 1986 | DR-764 | Major disaster | Flood | Severe Storms & Flooding | Public assistance |
| 17 Jun 1976 | EM-3015 | Emergency | Drought | Drought | 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
| Year of loss | Claims | Paid claims | Amount paid | Average paid |
|---|---|---|---|---|
| 2026 | 1 | 1 | $28,169 | $28,169 |
| 2020 | 4 | 2 | $115,781 | $57,890 |
| 2012 | 1 | 0 | $0 | — |
| 2011 | 54 | 45 | $1,695,030 | $37,667 |
| 2010 | 32 | 27 | $458,971 | $16,999 |
| 2003 | 9 | 2 | $6,544 | $3,272 |
| 2002 | 4 | 2 | $56,165 | $28,082 |
| 2001 | 11 | 9 | $182,486 | $20,276 |
| 2000 | 5 | 1 | $50,000 | $50,000 |
| 1999 | 82 | 66 | $1,060,747 | $16,072 |
| 1998 | 35 | 24 | $306,035 | $12,751 |
| 1997 | 9 | 9 | $53,533 | $5,948 |
| 1996 | 2 | 2 | $70,000 | $35,000 |
| 1995 | 2 | 2 | $1,459 | $729 |
| 1994 | 6 | 6 | $83,909 | $13,985 |
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
| Hazard (NRI) | Risk rating | Expected annual loss |
|---|---|---|
| Cold wave | $2,227,794 | |
| Inland flooding | $1,910,409 | |
| Strong wind | $1,118,283 | |
| Tornado | $695,065 | |
| Hail | $416,376 | |
| Wildfire | $259,025 | |
| Ice storm | $243,095 | |
| Winter weather | $217,360 | |
| Heat wave | $65,113 | |
| Earthquake | $12,243 | |
| Lightning | $8,330 | |
| Landslide | $599 | |
| Drought | $126 |
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 Day County, SD?
NCEI records 207 hail events in Day County since 1950, in 45 different years; that is about 2.7 recorded events a year. 40 reports were golf-ball size (1.75 in) or larger.
Has Day County had a tornado?
Yes. NCEI records 33 tornadoes in Day County since 1950, 2 of them rated (E)F2 or stronger. Tornado deaths recorded: 0.
When was the last federal disaster declaration for Day County?
1 Sep 2026: Severe Storms, Straight-Line Winds, Tornadoes, And Flooding, a major disaster declaration for severe storm. The county appears in 25 declarations since 1953.
How many flood insurance claims have been filed in Day County, and how much was paid?
257 NFIP claims since 1978, 198 of them paid, for $4.2M in total. FEMA publishes these figures redacted and aggregated; individual properties are not identified.
Is Day 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, "Relatively High" for social vulnerability and "Very High" for community resilience. These ratings are FEMA's relative comparison across all US counties.
How does Day County compare with the rest of South Dakota?
72.6 recorded events per 100 square miles against 73.7 statewide, and 47.5 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.