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Cass County, North Dakota

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

Relatively Moderate overall risk
2nd of 53highest risk in North Dakota
$82Mexpected losses a year
33federal declarations
1 in 22homes with flood insurance
Photo: U.S. Geological Survey, public domain

Cass County, North Dakota has a moderate overall risk from natural hazards in FEMA's National Risk Index. Its risk score is higher than 82% of US counties. It ranks 2nd of 53 counties in North Dakota. The costliest hazards here are inland flooding, tornadoes and cold waves. FEMA estimates about $82 million a year in expected losses, or roughly $444 per resident. Since 1965 it has been included in 33 federal disaster or emergency declarations for natural events (29 major disasters). The most recent was in September 2025 (severe storm, tornadoes and straight-line winds). About 1 in 22 homes here carry federal flood insurance (2,113 policies). Since 1978, federal flood insurance has paid about $25 million on 3,345 claims here, including $10 million for floods in 1997.

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

Top risks in Cass County

$34.2 million a yearExpected losses. Damaging events about 2 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
$11.8 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.

Cold wave

Moderate
$10.2 million a yearExpected losses. Damaging events about 19 times a year.
  • Insulate pipes in outside walls, crawl spaces and garages.
  • Know how to shut off the main water valve.
HazardRatingScoreExpected loss a year
Inland floodingModerate80.6
$34M
TornadoModerate89.7
$12M
Cold waveModerate88.1
$10M
Strong windVery High98.3
$10M
HailHigh96.8
$7M
Winter weatherVery High99.6
$4M
Ice stormVery High96.0
$3M
Heat waveLow57.1
$868K
LightningModerate63.2
$640K
WildfireVery Low50.5
$83K
EarthquakeVery Low24.1
$69K
DroughtVery Low20.2
$7K
LandslideVery Low33.8
$699

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 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 Cass County. 2020s bar runs to November 2026.

By type

Flood22
Severe Storm9
Coastal Storm1
Winter Storm1

Most recent

Sep 11, 2025Severe Storm, Tornadoes, and Straight-Line WindsMajor disaster
Feb 15, 2024Severe Winter Storm and Straight-Line WindsMajor disaster
Jul 9, 2020FloodingMajor disaster
Jun 12, 2019FloodingMajor disaster
May 29, 2013FloodingMajor disaster
Apr 26, 2013FloodingEmergency
May 10, 2011FloodingMajor disaster
Apr 7, 2011FloodingEmergency
Apr 30, 2010FloodingMajor disaster
Mar 14, 2010FloodingEmergency
Show all 33
Mar 24, 2009Severe Storms and FloodingMajor disaster
Sep 7, 2007Severe Storms and TornadoesMajor disaster
Jul 17, 2007Severe Storms and FloodingMajor disaster
Jun 5, 2006Severe Storms, Flooding, and Ground SaturationMajor disaster
Jan 4, 2006Severe Winter StormMajor disaster
Sep 13, 2005Hurricane Katrina EvacuationEmergency
May 28, 2001Severe Storms, Flooding, & Ground SaturationMajor disaster
Jun 27, 2000Severe Storms, Flooding and Ground SaturationMajor disaster
Jun 8, 1999Severe Storms, Flooding, Snow, Ice, Ground Saturation, Lanslides, Mudslides, and TorMajor disaster
Jun 15, 1998Flooding, Ground Saturation,Severe StormsMajor disaster
Apr 7, 1997Severe Flooding,Severe Winter Storms, Snowmelt, Spring RainsMajor disaster
Jan 12, 1997Severe Winter Storms and Blizzard ConditionsMajor disaster
Jun 5, 1996Severe Storms,Flooding, & Ice JamsMajor disaster
Jul 26, 1993Severe Storms & FloodingMajor disaster
May 8, 1989FloodingMajor disaster
Apr 26, 1979Severe Storms, Snowmelt & FloodingMajor disaster
Apr 17, 1978Storms, Ice Jams, Snowmelt & FloodingMajor disaster
Jul 11, 1975Severe Storms & FloodingMajor disaster
May 24, 1975Flooding From Rains & SnowmeltMajor disaster
Jun 5, 1970Severe Storms & FloodingMajor disaster
Apr 18, 1969FloodingMajor disaster
Mar 23, 1966FloodingMajor disaster
May 10, 1965FloodingMajor disaster

North Dakota also had 25 statewide declarations that did not name single counties.

Storm history since 1950

Tornado risk by county ›

The National Weather Service has logged 1,111 storm reports in Cass County since 1950, with 17 deaths and 117 injuries and about $435 million in reported damage. The strongest on record here was an F5 tornado on June 20, 1957.

109tornadoes
498hail reports, largest 4.5 inches
420damaging thunderstorm winds
74floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
Jun 20, 1957F5–103 / 10
Jun 20, 2025EF4Elizabeth0 / 3
Jun 13, 1950F3–0 / 0
Aug 30, 1956F3–8 / 0
Jun 15, 1973F3–0 / 0

Most damaging storms

DateTypeNearDamage
Jun 19, 2000Flash FloodFargo$100M
Jul 4, 1999Thunderstorm WindFargo$80M
Sep 21, 2007HailFargo$30M
Jun 20, 1957Tornado–$25M
Jul 15, 2007HailEmbden$25M
Jul 15, 2007Thunderstorm WindTower City$23M

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 Cass County

Check your address flood zone ›
4.5%of homes have federal flood insurance (2,113 policies)
49%of homes in mapped high-risk flood zones are insured
$24.8 millionpaid on 3,345 flood claims since 1978
1997costliest year, with $10.2 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 Cass County

$298,000median home value (North Dakota $249,900, US $332,700)
1993median year homes were built (North Dakota 1982, US 1980)
35%of homes built before 1980, before many modern wind, quake and flood building rules
1.9%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; 89,038 housing units.

Compare in North Dakota

All 53 ›
Largest countiesOverall riskTop hazard
Cass CountyModerateInland flooding
Burleigh CountyModerateInland flooding
Grand Forks CountyLowInland flooding
Ward CountyLowCold wave
Williams CountyLowCold wave
Stark CountyVery LowCold wave
Morton CountyLowInland flooding
Stutsman CountyLowCold wave

Neighboring counties

CountyOverall riskDeclarations
Clay County, MNLow27
Richland CountyVery Low35
Barnes CountyLow33
Traill CountyVery Low34
Norman County, MNVery Low30
Ransom CountyVery Low34
Steele CountyVery Low29

Cities in Cass County

Common questions about Cass County

What is the biggest natural hazard in Cass County?

Inland flooding has the highest expected yearly losses in Cass County, about $34.2 million a year in FEMA's estimate. Tornado is second at $11.8 million.

How many federal disasters has Cass County had?

Cass County has been included in 33 federal disaster or emergency declarations for natural events since 1965, including 29 major disasters. The most recent was Severe Storm, Tornadoes, and Straight-Line Winds in September 2025.

Is Cass County a high-risk place to live?

Its overall rating is Relatively Moderate, 2nd highest of 53 in North 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 Cass County?

Standard home insurance does not cover flooding. About 1 in 22 homes in Cass 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 Cass County had?

NOAA records list 109 tornadoes in Cass County since 1950. The strongest was an F5 tornado on June 20, 1957. The weather service has also logged 498 hail reports and 74 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.