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Natural hazard risk in Cass County, North Dakota

Updated October 30, 2026. Based on FEMA, NOAA and OpenFEMA data. Published by Humblebee.

FEMA overall Risk Index rating: Relatively Moderate (score 82.3 of 100)[5]

Expected annual loss (FEMA)
$81.8 million[1]
Federal disaster declarations since 1965
33[2]
NFIP flood claims paid, 1978 to 2026
$24.8 million[3]
Tornadoes recorded, 1950 to 2024
96[4]

FEMA's National Risk Index rates overall natural hazard risk in Cass County, North Dakota as Relatively Moderate compared with other US counties, with a score of 82.3 out of 100[5]. Within the county, the hazards with the highest FEMA scores are winter weather, strong wind and hail[6].

FEMA risk ratings for each hazard

Ratings and expected losses from the FEMA National Risk Index. Each rating compares this county with all US counties for that hazard, from Very Low to Very High. They are planning estimates, not predictions, and they do not describe any single property.

FEMA estimates Expected Annual Loss from all 18 natural hazards in Cass County at $81.8 million a year[1]. This is a FEMA estimate of average yearly loss, not money anyone paid, and FEMA says the index does not predict next year's losses[7]. By FEMA's estimate, the largest shares come from inland flooding at $34.2 million a year, tornado at $11.8 million a year and cold wave at $10.2 million a year[8]. FEMA rates Social Vulnerability as Very Low (score 10.6)[9]. This describes how susceptible social groups are to harm from natural hazards[9]. FEMA rates Community Resilience as Very High (score 93.4) compared with other US counties[10].

Hazards sorted by FEMA hazard-type Risk Index score, highest first
HazardFEMA risk ratingExpected annual loss
Winter WeatherVery High$3.9 million[11]
Strong WindVery High$10.1 million[12]
HailRelatively High$6.8 million[13]
Ice StormVery High$3.2 million[14]
TornadoRelatively Moderate$11.8 million[15]
Cold WaveRelatively Moderate$10.2 million[16]
Inland FloodingRelatively Moderate$34.2 million[17]
LightningRelatively Moderate$640,000[18]
Heat WaveRelatively Low$868,000[19]
WildfireVery Low$83,000[20]
LandslideVery Low$699[21]
EarthquakeVery Low$69,000[22]
DroughtVery Low$7,038[23]

Rated Not Applicable by FEMA for this county: avalanche, coastal flooding, hurricane, tsunami, volcanic activity[24].

Social vulnerability and community resilience

FEMA uses these two ratings to scale expected losses into the Risk Index.

FEMA measureRatingScore
Social vulnerabilityVery Low10.6[9]
Community resilienceVery High93.4[10]

Flooding and flood insurance

FEMA rates inland flooding risk in Cass County Relatively Moderate, with an Expected Annual Loss of $34.2 million a year[17]. OpenFEMA lists 2,113 residential flood insurance contracts in force out of 47,318 residential structures, as of 2026-08-03[25]. Inside FEMA's mapped Special Flood Hazard Area, OpenFEMA lists 1,319 residential flood insurance contracts for 2,691 residential structures, a rate of 49%[25]. HazardFacts tallied 3,345 NFIP claims for losses in the county from 1978 to 2026, and NFIP paid $24.8 million in total[3]. To learn the flood zone of an address, use FEMA's Flood Map Service Center[26].

Measure Value
Inland Flooding, FEMA risk rating[17] Relatively Moderate, $34.2 million expected loss a year
NFIP residential flood policies in force (2026)[25] 2,113 of 47,318 homes
Homes in FEMA's mapped high-risk flood area (SFHA)[25] 2,691, of which 1,319 insured
NFIP flood claims, 1978 to 2026[3] 3,345 filed, $24.8 million paid

Is a specific address in a flood zone? Only FEMA's flood maps answer that, property by property[26]. This page describes the whole county.

Search an address on the FEMA Flood Map Service Center

Disaster declarations and tornado records

OpenFEMA lists 33 federal disaster declarations for natural hazards that include Cass County since 1965, and 22 of them were for flood[2]. The most recent is DR-4888-ND, a severe storm with tornadoes and straight-line winds, declared 2025-09-11[27]. NOAA's tornado database records 96 tornadoes touching the county from 1950 to 2024[4]. The most recent recorded tornado was on 2021-08-20[4].

Federal disaster declarations for natural hazards that include Cass County, since 1965
Incident type Declarations
Flood[2] 22
Severe Storm[2] 9
Winter Storm[2] 1
Coastal Storm[2] 1
Most recent declarations
Declaration Incident Declared
DR-4888-ND[27] Severe Storm, Tornadoes, And Straight-Line Winds 2025-09-11
DR-4760-ND[27] Severe Winter Storm And Straight-Line Winds 2024-02-15
DR-4553-ND[27] Flooding 2020-07-09
DR-4444-ND[27] Flooding 2019-06-12
DR-4118-ND[27] Flooding 2013-05-29

How to prepare

Steps from Ready.gov, FEMA's preparedness site, for the hazards with the highest FEMA ratings here. Follow instructions from local officials and the National Weather Service when a warning is issued.

Winter storms and cold

Before

  • Insulate your home and learn how to keep pipes from freezing.
  • Install and test smoke and carbon monoxide detectors with battery backup.
  • Keep several days of supplies in case the power goes out, including medication and pet needs.
  • Put an emergency kit in your car with jumper cables, sand, blankets, water and snacks, and keep the tank full.

During

  • Under a winter storm warning, find shelter right away.
  • Stay off the roads if you can. If you are stuck in your car, stay inside it.
  • Run generators and grills only outdoors, away from windows, and never heat your home with an oven or stove.

Source: Ready.gov, winter storms and cold

Tornadoes

Before

  • Learn the warning signs: a rotating funnel cloud, an approaching cloud of debris or a loud roar like a freight train.
  • Sign up for community warning systems and learn what your local sirens sound like.
  • Pick a safe spot, such as a safe room built to FEMA criteria or an ICC 500 storm shelter, and practice getting there.
  • Include your pets in the household emergency plan.
  • Keep supplies, food, water and medication in case you have to stay home for a long time.

During

  • Go right away to the safe place you picked in advance.
  • Protect your head and neck with your arms and stay away from windows, doors and outside walls.
  • No place in a car is fully safe. If you can get lower than the road, leave the car and lie down there.

Source: Ready.gov, tornadoes

Floods

Before

  • Check your flood risk with FEMA's Flood Map Service Center, and remember that floods do not follow map lines.
  • Sign up for your community's warning system. NOAA Weather Radio also broadcasts alerts.
  • Buy flood insurance through the NFIP well before a disaster. Homeowners policies do not cover flooding, and a new policy typically takes up to 30 days to go into effect.
  • Make a household plan with evacuation routes, shelter locations and what to do in a flash flood.
  • Keep important documents in a waterproof container and make password-protected digital copies.

During

  • If you are told to evacuate, leave right away and never drive around barricades.
  • Do not walk, swim or drive through floodwater. Six inches of moving water can knock you down.
  • If you are trapped in a building, go to the highest level, but do not climb into a closed attic.

Source: Ready.gov, floods

Questions people ask

Is Cass County, ND at risk of flooding?
FEMA rates inland flooding risk Relatively Moderate compared with other US counties, and it estimates $34.2 million a year in expected losses from it[17]. For a specific address, check FEMA's Flood Map Service Center[26].
Does Cass County, ND get tornadoes?
NOAA's tornado database records 96 tornadoes touching the county from 1950 to 2024[4]. FEMA rates tornado risk Relatively Moderate compared with other US counties[15].
How many disasters have been declared in Cass County, ND?
OpenFEMA lists 33 federal disaster declarations for natural hazards that include the county since 1965[2].
Is Cass County, ND at risk of earthquakes or hurricanes?
FEMA rates earthquake risk Very Low compared with other US counties[22]. FEMA rates hurricane Not Applicable for the county[24].
Is Cass County, ND at risk of wildfire?
FEMA rates wildfire risk Very Low compared with other US counties, with an Expected Annual Loss of $83,000 a year[20].

Facts and sources

  1. FEMA National Risk Index (version 1.20, December 2025): Expected Annual Loss from all 18 natural hazards in Cass County is $81.8 million a year (Expected Annual Loss rating Relatively Moderate, score 89.0). Of this, buildings account for $56.8 million, injuries and deaths (converted to dollars by FEMA) for $15.4... FEMA National Risk Index
  2. OpenFEMA Disaster Declarations Summaries list 33 federal disaster declarations for natural hazards that include Cass County since 1965 (29 major disaster, 4 emergency or fire management). By incident type: flood 22, severe storm 9, winter storm 1, coastal storm 1. Biological (such as COVID-19) and other non-natural... OpenFEMA Disaster Declarations
  3. HazardFacts tally of OpenFEMA NFIP Redacted Claims (losses from 1978 to 2026): 3,345 National Flood Insurance Program claims were filed for losses in Cass County, 2,877 of them with a payment, and NFIP paid $24.8 million in total (building, contents and increased cost of compliance, in dollars of the year paid).... OpenFEMA NFIP claims
  4. NOAA Storm Prediction Center tornado database (1950 to 2024): 96 recorded tornadoes touched Cass County. The strongest were rated F3 (most recent of them on 1973-06-15). 3 were rated F3/EF3 or stronger. The most recent recorded tornado was on 2021-08-20. Ratings used the Fujita scale until early 2007 and the... NOAA Storm Prediction Center
  5. FEMA National Risk Index (version 1.20, December 2025): the overall natural hazard Risk Index rating for Cass County is Relatively Moderate, with a Risk Index score of 82.3 out of 100. The score is the county's percentile rank among all US counties. FEMA National Risk Index
  6. Among the 18 hazards in the FEMA National Risk Index (version 1.20, December 2025), the hazards with the highest hazard-type Risk Index scores for Cass County are winter weather (99.5, Very High), strong wind (98.2, Very High), hail (96.7, Relatively High). HazardFacts sorted FEMA's published scores; FEMA's scores... FEMA National Risk Index
  7. FEMA's National Risk Index FAQ (December 2025): Expected Annual Loss is FEMA's estimate of the average economic loss in dollars from natural hazards each year. The index is not meant to predict how much damage a community will have in the next year, and a hazard can still cause damage where a rating is low. Scores... FEMA National Risk Index documentation
  8. HazardFacts sorted FEMA's hazard-type Expected Annual Loss values for Cass County (National Risk Index v1.20): the largest are inland flooding ($34.2 million a year), tornado ($11.8 million a year), cold wave ($10.2 million a year), out of $81.8 million a year from all 18 hazards. FEMA National Risk Index
  9. FEMA National Risk Index (version 1.20, December 2025): Social Vulnerability rating for Cass County is Very Low (score 10.6). FEMA describes social vulnerability as how susceptible social groups are to the harm natural hazards cause. FEMA National Risk Index
  10. FEMA National Risk Index (version 1.20, December 2025): Community Resilience rating for Cass County is Very High (score 93.4). FEMA describes community resilience as a community's ability to prepare for, withstand and recover from hazards. FEMA National Risk Index
  11. FEMA National Risk Index (version 1.20, December 2025), winter weather in Cass County: Risk Index rating Very High (score 99.5 of 100). Expected Annual Loss $3.9 million a year (rating Very High). Annualized frequency 24.26 events per year, from recorded occurrences over a period of record of 18 years. FEMA National Risk Index
  12. FEMA National Risk Index (version 1.20, December 2025), strong wind in Cass County: Risk Index rating Very High (score 98.2 of 100). Expected Annual Loss $10.1 million a year (rating Very High). Annualized frequency 2.54 events per year, from recorded occurrences over a period of record of 38 years. FEMA National Risk Index
  13. FEMA National Risk Index (version 1.20, December 2025), hail in Cass County: Risk Index rating Relatively High (score 96.7 of 100). Expected Annual Loss $6.8 million a year (rating Relatively High). Annualized frequency 4.19 events per year, from recorded occurrences over a period of record of 37 years. FEMA National Risk Index
  14. FEMA National Risk Index (version 1.20, December 2025), ice storm in Cass County: Risk Index rating Very High (score 95.9 of 100). Expected Annual Loss $3.2 million a year (rating Very High). Annualized frequency 0.43 event-days per year, from recorded occurrences over a period of record of 68 years. FEMA National Risk Index
  15. FEMA National Risk Index (version 1.20, December 2025), tornado in Cass County: Risk Index rating Relatively Moderate (score 89.6 of 100). Expected Annual Loss $11.8 million a year (rating Relatively High). Annualized frequency 1.24 events per year, from recorded occurrences over a period of record of 38 years. FEMA National Risk Index
  16. FEMA National Risk Index (version 1.20, December 2025), cold wave in Cass County: Risk Index rating Relatively Moderate (score 88.1 of 100). Expected Annual Loss $10.2 million a year (rating Relatively High). Annualized frequency 18.58 event-days per year, from recorded occurrences over a period of record of 18 years. FEMA National Risk Index
  17. FEMA National Risk Index (version 1.20, December 2025), inland flooding in Cass County: Risk Index rating Relatively Moderate (score 80.6 of 100). Expected Annual Loss $34.2 million a year (rating Relatively Moderate). Annualized frequency 2.18 event-days per year, from recorded occurrences over a period of record... FEMA National Risk Index
  18. FEMA National Risk Index (version 1.20, December 2025), lightning in Cass County: Risk Index rating Relatively Moderate (score 63.1 of 100). Expected Annual Loss $640,000 a year (rating Relatively Moderate). Annualized frequency 29.59 events per year, from recorded occurrences over a period of record of 24 years. FEMA National Risk Index
  19. FEMA National Risk Index (version 1.20, December 2025), heat wave in Cass County: Risk Index rating Relatively Low (score 57.1 of 100). Expected Annual Loss $868,000 a year (rating Relatively Low). Annualized frequency 1.63 event-days per year, from recorded occurrences over a period of record of 18 years. FEMA National Risk Index
  20. FEMA National Risk Index (version 1.20, December 2025), wildfire in Cass County: Risk Index rating Very Low (score 50.5 of 100). Expected Annual Loss $83,000 a year (rating Very Low). FEMA's modeled annual frequency is 0.0005 events per year. FEMA National Risk Index
  21. FEMA National Risk Index (version 1.20, December 2025), landslide in Cass County: Risk Index rating Very Low (score 33.8 of 100). Expected Annual Loss $699 a year (rating Very Low). FEMA National Risk Index
  22. FEMA National Risk Index (version 1.20, December 2025), earthquake in Cass County: Risk Index rating Very Low (score 24.1 of 100). Expected Annual Loss $69,000 a year (rating Very Low). FEMA's modeled annual frequency is 0.0001 events per year. FEMA National Risk Index
  23. FEMA National Risk Index (version 1.20, December 2025), drought in Cass County: Risk Index rating Very Low (score 20.2 of 100). Expected Annual Loss $7,038 a year (rating Very Low). Annualized frequency 1.57 event-days per year, from recorded occurrences over a period of record of 22 years. FEMA National Risk Index
  24. FEMA National Risk Index (version 1.20, December 2025) rates these hazards Not Applicable for Cass County: avalanche, coastal flooding, hurricane, tsunami, volcanic activity. FEMA uses Not Applicable when its source data has no historical record of the hazard in the community and the hazard is not considered... FEMA National Risk Index documentation
  25. NFIP Residential Penetration Rates (OpenFEMA, as of 2026-08-03): 2,113 residential flood insurance contracts were in force in Cass County, out of 47,318 residential structures, a penetration rate of 4.5%. Inside FEMA's mapped Special Flood Hazard Area there were 2,691 residential structures and 1,319 contracts, a... OpenFEMA NFIP penetration rates
  26. FEMA's Flood Map Service Center is the official public source for flood maps (Flood Insurance Rate Maps) produced under the National Flood Insurance Program. Flood zones apply to specific properties: look up an address there or ask the local floodplain manager. County-level ratings do not tell you the flood zone of... FEMA Flood Map Service Center
  27. Most recent federal disaster declarations for natural hazards (table on this page). OpenFEMA Disaster Declarations

FEMA's National Risk Index compares each county with all other US counties. Ratings are relative (Very Low to Very High), not a measure of safety. Never call a place safe, unsafe, good or bad to live in. Risk Index and Expected Annual Loss values are FEMA estimates for planning. They do not predict next year's losses and do not apply to a single property. Flood zones are set by FEMA flood maps for specific properties. County ratings and flood insurance counts do not tell anyone whether an address is in a flood zone. Disaster declaration, NFIP and tornado counts are records of the past for this county only. Do not compare with other counties unless a fact does.

Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties, v1.20 (December 2025). Retrieved from fema.maps.arcgis.com on October 30, 2026. This product uses the Federal Emergency Management Agency's National Risk Index dataset API or downloadable datasets but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s). This product uses the FEMA OpenFEMA API, but is not endorsed by FEMA.