3,345 flood insurance claims·$24.8M paid·23 federal flood & hurricane disasters
Share of the whole county outline, rivers and lakes included; parts FEMA hasn’t mapped count as zero.
Shaded areas are FEMA’s mapped flood hazard zones in and around Cass County, North Dakota. Zoomed out they are simplified; at street level the map switches to FEMA’s exact layer. Tap anywhere to check that spot, or search an address above.
Flash flooding from summer thunderstorms dominates the flood profile of Cass County, which has recorded 50 flash flood events and 37 general flood events resulting in 3 deaths over the last 30 years according to the NOAA Storm Events Database. Recent occurrences include severe supercell thunderstorms and a derecho that produced heavy rainfall in June 2025, followed by thunderstorm clusters that caused localized flash flooding in August 2025.
Federal insurance records indicate that flood risks extend across multiple zones, with the highest volume of claims occurring in Zone A with 1,720 claims averaging an 9-inch recorded water depth and a $10,055 payout. Properties in Zone X account for 1,136 claims with an average 6-inch water depth and $6,546 payout, while Shaded Zone X properties recorded 183 claims averaging a 12-inch water depth and a $13,774 payout.
Homeowners, real estate agents, and journalists should pay the closest attention to properties located within Zone A and Shaded Zone X, as these areas experience higher average water depths and larger claim payouts during flood events.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
13% of Cass County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
1,969 NFIP claims with a recorded rated flood zone, 1978 to date. The zone is the one FEMA used to rate that policy, which may not match today’s map. Source: OpenFEMA NFIP claims.
In flood insurance claims here that reported a flood depth, the average was 8 inches.
Drawn to scale against an 80-inch door. Even a few inches soaks flooring, the bottom of the drywall and anything plugged in near the floor.
Average of the depths reported on claims (zero and implausible values left out); FEMA’s record doesn’t say exactly where each depth was measured. Source: OpenFEMA NFIP claims.
The worst year was 1997, with 1,201 claims and $10.2M paid, the year of Severe Winter Storms and Blizzard Conditions and Severe Flooding,severe Winter Storms, Snowmelt, Spring Rains.
Bar height is scaled by square root so ordinary years stay visible next to the worst one. NFIP claims by year of loss. Source: OpenFEMA.
24 NOAA storm reports from Cass County describe what happened, in the words of the forecasters who covered it. Read the North Dakota flood stories →
35 federal disaster declarations since 1965, 23 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Storm, Tornadoes, And Straight-line Winds | Jun 20, 2025 |
| Severe Winter Storm And Straight-line Winds | Dec 25, 2023 |
| Flooding | Apr 1, 2020 |
| Flooding | Mar 21, 2019 |
| Flooding | Apr 22, 2013 |
| Flooding | Apr 5, 2011 |
| Flooding | Feb 14, 2011 |
| Flooding | Feb 26, 2010 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
87 since 1996: 50 flash floods and 37 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | Jun 20, 2025 | — |
| Flash Flood | Aug 5, 2025 | — |
| Flood | May 21, 2024 | $500 |
| Flood | Dec 26, 2023 | — |
| Flood | Apr 20, 2023 | $951,000 |
| Flood | Apr 19, 2023 | $951,000 |
| Flood | Apr 17, 2023 | $951,000 |
| Flood | Apr 16, 2023 | $951,000 |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flash Flood · Jun 20, 2025. During the evening of Friday, June 20th into the early morning hours of June 21st, much of the region was affected by severe weather. Supercell thunderstorms developed across southeast North Dakota ahead of an approaching convective complex, producing multiple strong, destructive, and fatal tornadoes. This was followed by a powerful line of severe thunderstorms categorized as a derecho, which tracked across much o…
Flash Flood · Aug 5, 2025. A cluster of thunderstorms produced heavy rain and localized flash flooding over parts of southeast North Dakota during the evening. A wake low developed as this complex moved east with widespread 50 to 55 mph winds reported, and one brief high wind report of 58 mph at Fargo Airport.
Flood · May 21, 2024. Excessive rainfall lead to late May river flooding along the Red River and its tributaries.
Flood · Dec 26, 2023. Rain and above normal temperatures in the southern Red River Valley lead to flood warnings being issued for three sites in southeastern North Dakota. The rain fell on frozen ground, and thus immediately entered the river system.
National Weather Service narratives, lightly trimmed. Source: NOAA Storm Events Database.
Every colour on the map above is a place on this drawing: where the ground sits relative to the flood FEMA plans for.
If a building in Cass County is in a high-risk zone (A or V) and its mortgage comes from a federally regulated or insured lender, or is federally backed, flood insurance is required.
Outside those zones it is optional, and often worth having: from 2014 to 2024 nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area. Since Risk Rating 2.0, NFIP premiums are set for each building, so the only reliable price is a quote: FloodSmart.gov or a local agent.