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Day County, South Dakota

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

Very Low overall risk
26th of 66highest risk in South Dakota
$7Mexpected losses a year
23federal declarations
1 in 333homes with flood insurance
Photo: Bold Frontiers, CC BY 2.0

Day County, South Dakota has a very low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 72% of US counties. It ranks 26th of 66 counties in South Dakota. The costliest hazards here are cold waves, inland flooding and strong wind. FEMA estimates about $7.2 million a year in expected losses, or roughly $1,317 per resident. Since 1976 it has been included in 23 federal disaster or emergency declarations for natural events (21 major disasters). The most recent was in September 2026 (severe storms, straight-line winds, tornadoes and flooding). Only 12 homes here carry federal flood insurance. Since 1978, federal flood insurance has paid about $4.2 million on 257 claims here, including $1.7 million for floods in 2011.

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

Top risks in Day County

Cold wave

Moderate
$2.2 million a yearExpected losses. Damaging events about 14 times a year.
  • Insulate pipes in outside walls, crawl spaces and garages.
  • Know how to shut off the main water valve.
$1.9 million a yearExpected losses. Damaging events about once 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.

Strong wind

Moderate
$1.1 million a yearExpected losses. Damaging events about 3 times a year.
  • Secure outdoor furniture and trash bins before storms.
  • Have trees near the house checked.
HazardRatingScoreExpected loss a year
Cold waveModerate76.0
$2M
Inland floodingVery Low20.0
$2M
Strong windModerate82.1
$1M
TornadoLow40.6
$695K
HailLow69.0
$416K
WildfireLow77.9
$259K
Ice stormModerate76.1
$243K
Winter weatherModerate85.1
$217K
Heat waveVery Low23.2
$65K
EarthquakeVery Low14.7
$12K
LightningVery Low3.1
$8K
LandslideVery Low42.1
$599
DroughtVery Low13.6
$126

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 high 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 Day County. 2020s bar runs to November 2026.

By type

Severe Storm11
Flood9
Drought1
Coastal Storm1
Winter Storm1

Most recent

Sep 1, 2026Severe Storms, Straight-Line Winds, Tornadoes, and FloodingMajor disaster
Jul 6, 2023FloodingMajor disaster
Feb 27, 2023Severe Winter Storms and SnowstormMajor disaster
Jun 29, 2022Severe Storm, Straight-Line Winds, Tornadoes, and FloodingMajor disaster
Nov 18, 2019Severe Storms, Tornadoes, and FloodingMajor disaster
Jun 7, 2019Severe Winter Storm, Snowstorm, and FloodingMajor disaster
Feb 1, 2017Severe Winter StormMajor disaster
May 13, 2011FloodingMajor disaster
May 13, 2010FloodingMajor disaster
Mar 10, 2010Severe Winter StormMajor disaster
Show all 23
Jun 16, 2009Severe Storms and FloodingMajor disaster
May 22, 2007Severe Storms, Tornadoes, and FloodingMajor disaster
Dec 20, 2005Severe Winter StormMajor disaster
Sep 10, 2005Hurricane Katrina EvacuationEmergency
May 17, 2001Severe Winter Storms, Flooding, and Ice JamsMajor disaster
Jun 1, 1998Flooding, Severe Storms, TornadoesMajor disaster
Apr 7, 1997Severe Flooding, Sever Winter Storms,Heavy Rains High WindsMajor disaster
Jan 10, 1997Severe Winter Storms and Blizzard ConditionsMajor disaster
May 26, 1995FloodingMajor disaster
Jun 21, 1994Severe Storms and FloodingMajor disaster
Jul 19, 1993Severe Storms, Tornadoes & FloodingMajor disaster
May 3, 1986Severe Storms & 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 469 storm reports in Day County since 1953, with 0 deaths and 15 injuries and about $15.2 million in reported damage. The strongest on record here was an F2 tornado on July 17, 1996 near Pierpont.

33tornadoes
208hail reports, largest 4 inches
198damaging thunderstorm winds
30floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
Jul 17, 1996F2Pierpont0 / 0
Jun 15, 1953F2–0 / 0
Jun 19, 1979F1–0 / 0
Jun 25, 1973F1–1 / 0
Jun 11, 1954F1–0 / 0

Most damaging storms

DateTypeNearDamage
Jun 1, 2019FloodPierpont$12M
Jun 19, 1979Tornado–$3M
Jun 24, 1994Hail–$550K
Apr 12, 2023FloodPierpont$300K
Jul 17, 1996TornadoPierpont$200K
Apr 1, 2019FloodPierpont$104K

Source: NOAA Storm Events Database, county-based reports through Jul 30, 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 Day County

Check your address flood zone ›
0.3%of homes have federal flood insurance (12 policies)
0%of homes in mapped high-risk flood zones are insured
$4.2 millionpaid on 257 flood claims since 1978
2011costliest year, with $1.7 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 Day County

$173,600median home value (South Dakota $257,400, US $332,700)
1967median year homes were built (South Dakota 1980, US 1980)
67%of homes built before 1980, before many modern wind, quake and flood building rules
4.3%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; 3,440 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
Brown CountyLow17
Codington CountyLow21
Roberts CountyVery Low22
Grant CountyVery Low20
Spink CountyVery Low21
Marshall CountyVery Low18
Clark CountyVery Low20

Common questions about Day County

What is the biggest natural hazard in Day County?

Cold wave has the highest expected yearly losses in Day County, about $2.2 million a year in FEMA's estimate. Inland flooding is second at $1.9 million.

How many federal disasters has Day County had?

Day County has been included in 23 federal disaster or emergency declarations for natural events since 1976, including 21 major disasters. The most recent was Severe Storms, Straight-Line Winds, Tornadoes, and Flooding in September 2026.

Is Day County a high-risk place to live?

Its overall rating is Very Low, 26th 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 Day County?

Standard home insurance does not cover flooding. About 1 in 333 homes in Day 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 Day County had?

NOAA records list 33 tornadoes in Day County since 1950. The strongest was an F2 tornado on July 17, 1996 near Pierpont. The weather service has also logged 208 hail reports and 30 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.