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Mellette County, South Dakota

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

Very Low overall risk
58th of 66highest risk in South Dakota
$2Mexpected losses a year
12federal declarations
Photo: U.S. Geological Survey, public domain

Mellette County, South Dakota has a very low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 95% of US counties. It ranks 58th of 66 counties in South Dakota. The costliest hazards here are inland flooding, cold waves and wildfires. FEMA estimates about $1.9 million a year in expected losses, or roughly $992 per resident. Since 1976 it has been included in 12 federal disaster or emergency declarations for natural events (10 major disasters). The most recent was in February 2023 (severe winter storms and snowstorm). No homes here carry federal flood insurance.

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

Top risks in Mellette County

$657,180 a yearExpected losses. Damaging events about once every 2 years.
  • 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.
$442,542 a yearExpected losses. Damaging events about 5 times a year.
  • Insulate pipes in outside walls, crawl spaces and garages.
  • Know how to shut off the main water valve.
$347,853 a yearExpected losses. Damaging events about once every 615 years.
  • Clear dry plants and debris within 5 feet of the house.
  • Get home insurance quotes early; availability varies by area.
HazardRatingScoreExpected loss a year
Inland floodingVery Low8.1
$657K
Cold waveLow43.4
$443K
WildfireLow83.2
$348K
TornadoVery Low19.4
$133K
Strong windLow16.9
$88K
Winter weatherLow60.2
$54K
HailVery Low22.5
$48K
Ice stormLow33.1
$23K
LightningVery Low11.2
$22K
Heat waveVery Low15.1
$21K
DroughtVery Low30.8
$16K
EarthquakeVery Low15.9
$11K
LandslideVery Low23.2
$97

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 Mellette County. 2020s bar runs to November 2026.

By type

Severe Storm4
Flood4
Drought1
Coastal Storm1
Snowstorm1
Winter Storm1

Most recent

Feb 27, 2023Severe Winter Storms and SnowstormMajor disaster
Sep 23, 2019Severe Storms and FloodingMajor disaster
Jun 7, 2019Severe Winter Storm, Snowstorm, and FloodingMajor disaster
Mar 9, 2010Severe Winter Storm and SnowstormMajor disaster
Dec 12, 2008Severe Winter Storm and Record and Near Record SnowMajor disaster
Jul 9, 2008Severe Storms and FloodingMajor disaster
Sep 10, 2005Hurricane Katrina EvacuationEmergency
Jul 20, 2004Severe Storms and FloodingMajor disaster
May 17, 2001Severe Winter Storms, Flooding, and Ice JamsMajor disaster
Apr 7, 1997Severe Flooding, Sever Winter Storms,Heavy Rains High WindsMajor disaster
Show all 12
Jan 10, 1997Severe Winter Storms and Blizzard ConditionsMajor disaster
Jun 17, 1976DroughtEmergency

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

Storm history since 1966

Tornado risk by county ›

The National Weather Service has logged 307 storm reports in Mellette County since 1966, with 0 deaths and 1 injury and about $992,500 in reported damage. The strongest on record here was an F2 tornado on June 4, 1971.

12tornadoes
164hail reports, largest 4.5 inches
116damaging thunderstorm winds
14floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
Jun 4, 1971F2–0 / 0
May 19, 1974F1–0 / 0
Jul 4, 1973F1–0 / 0
Sep 24, 1986F0–0 / 0
Jul 10, 1987F0–0 / 0

Most damaging storms

DateTypeNearDamage
May 19, 1974Tornado–$250K
Aug 20, 2000Thunderstorm WindWhite River$200K
Jun 5, 2008FloodMosher$100K
Jul 9, 2007Thunderstorm WindWhite River$75K
Jul 22, 2012Thunderstorm WindWood$60K
May 3, 1994HailMosherand$55K

Source: NOAA Storm Events Database, county-based reports through Jun 29, 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 Mellette County

Check your address flood zone ›
0%of homes have federal flood insurance (0 policies)
0%of homes in mapped high-risk flood zones are insured
$0paid on 0 flood claims since 1978
n/acostliest year

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 Mellette County

$84,100median home value (South Dakota $257,400, US $332,700)
1969median year homes were built (South Dakota 1980, US 1980)
71%of homes built before 1980, before many modern wind, quake and flood building rules
21.4%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; 779 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
Todd CountyVery Low11
Tripp CountyVery Low18
Lyman CountyVery Low14
Bennett CountyVery Low13
Jackson CountyVery Low20
Jones CountyVery Low13

Common questions about Mellette County

What is the biggest natural hazard in Mellette County?

Inland flooding has the highest expected yearly losses in Mellette County, about $657,180 a year in FEMA's estimate. Cold wave is second at $442,542.

How many federal disasters has Mellette County had?

Mellette County has been included in 12 federal disaster or emergency declarations for natural events since 1976, including 10 major disasters. The most recent was Severe Winter Storms and Snowstorm in February 2023.

Is Mellette County a high-risk place to live?

Its overall rating is Very Low, 58th 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 Mellette 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 Mellette County had?

NOAA records list 12 tornadoes in Mellette County since 1950. The strongest was an F2 tornado on June 4, 1971. The weather service has also logged 164 hail reports and 14 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.