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Brown County, South Dakota

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

Relatively Low overall risk
4th of 66highest risk in South Dakota
$37Mexpected losses a year
17federal declarations
1 in 143homes with flood insurance
Photo: Bold Frontiers, CC BY 2.0

Brown County, South Dakota has a relatively low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is higher than 74% of US counties. It ranks 4th of 66 counties in South Dakota. The costliest hazards here are cold waves, inland flooding and tornadoes. FEMA estimates about $37 million a year in expected losses, or roughly $957 per resident. Since 1969 it has been included in 17 federal disaster or emergency declarations for natural events (15 major disasters). The most recent was in July 2023 (flooding). Fewer than 1 in 100 homes here carry federal flood insurance (114 policies). Since 1978, federal flood insurance has paid about $3.3 million on 484 claims here, including $1.9 million for floods in 2007.

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

Top risks in Brown County

$16.4 million a yearExpected losses. Damaging events about 13 times a year.
  • Insulate pipes in outside walls, crawl spaces and garages.
  • Know how to shut off the main water valve.
$11.3 million a yearExpected losses. Damaging events about 5 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.

Tornado

Moderate
$2.9 million a yearExpected losses. Damaging events about once a year.
  • Pick a shelter spot: a basement, or an inside room on the lowest floor with no windows.
  • Turn on emergency alerts on your phone and keep a weather radio.
HazardRatingScoreExpected loss a year
Cold waveHigh96.4
$16M
Inland floodingLow63.1
$11M
TornadoModerate70.1
$3M
Strong windModerate82.5
$2M
Winter weatherVery High98.2
$2M
HailModerate86.5
$2M
Ice stormModerate81.7
$534K
Heat waveLow48.7
$402K
WildfireLow77.1
$353K
EarthquakeVery Low27.8
$68K
DroughtVery Low30.6
$31K
LightningVery Low7.6
$27K
LandslideVery Low44.4
$1K

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 low 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 Brown County. 2020s bar runs to November 2026.

By type

Flood9
Severe Storm6
Drought1
Coastal Storm1

Most recent

Jul 6, 2023FloodingMajor disaster
Jun 7, 2019Severe Winter Storm, Snowstorm, and FloodingMajor disaster
May 13, 2011FloodingMajor disaster
May 13, 2010FloodingMajor disaster
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
Show all 17
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
Jun 17, 1976DroughtEmergency
Apr 18, 1969FloodingMajor disaster

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

Storm history since 1955

Tornado risk by county ›

The National Weather Service has logged 1,141 storm reports in Brown County since 1955, with 4 deaths and 33 injuries and about $46.8 million in reported damage. The strongest on record here was an F4 tornado on June 23, 2002 near Barnard.

84tornadoes
444hail reports, largest 4.5 inches
442damaging thunderstorm winds
165floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
Jun 23, 2002F4Barnard0 / 0
Jul 1, 1973F3–3 / 1
May 31, 1996F3Aberdeen1 / 0
Jun 25, 1969F3–6 / 0
May 20, 1965F3–0 / 0

Most damaging storms

DateTypeNearDamage
Jun 1, 2019FloodWinship$36M
May 5, 2007Flash FloodWarner$5M
Jun 19, 1979Tornado–$3M
May 31, 1996TornadoAberdeen$750K
Apr 1, 2019FloodWinship$745K
Apr 10, 2023FloodWinship$300K

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 Brown County

Check your address flood zone ›
0.7%of homes have federal flood insurance (114 policies)
8.1%of homes in mapped high-risk flood zones are insured
$3.3 millionpaid on 484 flood claims since 1978
2007costliest year, with $1.9 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 Brown County

$221,100median home value (South Dakota $257,400, US $332,700)
1973median year homes were built (South Dakota 1980, US 1980)
60%of homes built before 1980, before many modern wind, quake and flood building rules
5%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; 18,090 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
Spink CountyVery Low21
Day CountyVery Low23
Dickey County, NDVery Low30
Marshall CountyVery Low18
Edmunds CountyVery Low18
Sargent County, NDVery Low30
McPherson CountyVery Low15
Faulk CountyVery Low15

Cities in Brown County

Common questions about Brown County

What is the biggest natural hazard in Brown County?

Cold wave has the highest expected yearly losses in Brown County, about $16.4 million a year in FEMA's estimate. Inland flooding is second at $11.3 million.

How many federal disasters has Brown County had?

Brown County has been included in 17 federal disaster or emergency declarations for natural events since 1969, including 15 major disasters. The most recent was Flooding in July 2023.

Is Brown County a high-risk place to live?

Its overall rating is Relatively Low, 4th 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 Brown County?

Standard home insurance does not cover flooding. About 1 in 143 homes in Brown 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 Brown County had?

NOAA records list 84 tornadoes in Brown County since 1950. The strongest was an F4 tornado on June 23, 2002 near Barnard. The weather service has also logged 444 hail reports and 165 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.