63 flood insurance claims·$163,451 paid·7 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 Lyon County, Minnesota. 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.
Overland flooding and flash flooding from summer storms dominate the flood risks in Lyon County, Minnesota, supported by 37 recorded flood events and 27 flash flood events over the last 30 years. Heavy rainfall events frequently drive this activity, such as the slow-moving convective clusters and stationary boundaries that dropped 2 to 4 inches of rain across the area in August 2025.
National Flood Insurance Program records show that claims occur across multiple zones, with the highest concentration in high-risk areas. Specifically, Zone A accounts for 41 claims with an average payout of $4,402 and an average recorded water depth of 3 inches. Additional claims are recorded outside primary hazard areas, including 13 claims in Zone X averaging $5,414 with an average water depth of 1 inch, and 6 claims in Zone UNKNOWN averaging $8,454 with a 1-inch average water depth. Zone X_UNSHADED accounts for 2 claims averaging $6,084 with 0 inches of average recorded water depth, while Zone X_SHADED has 1 claim with a $0 payout and 0 inches of average water depth.
Property owners located in Zone A face the highest frequency of claims and should pay the closest attention to flood risk, though residents in Zone X and unmapped areas also experience insurance claims and property water accumulation.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
7% of Lyon County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
44 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 2 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 1993, with 29 claims and $59,366 paid, the year of Severe Storms, Tornadoes & Flooding.
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.
22 NOAA storm reports from Lyon County describe what happened, in the words of the forecasters who covered it. Read the Minnesota flood stories →
18 federal disaster declarations since 1969, 7 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Storms, Straight-line Winds, Tornadoes, And Flooding | May 29, 2022 |
| Severe Winter Storm, Straight-line Winds, And Flooding | Mar 12, 2019 |
| Severe Storms, Tornadoes, Straight-line Winds, And Flooding | Jun 15, 2018 |
| Severe Storms, Straight-line Winds, Flooding, Landslides, And Mudslides | Jun 11, 2014 |
| Severe Storms, Flooding, And Tornadoes | Jul 1, 2011 |
| Severe Storms And Flooding | Mar 16, 2011 |
| Severe Storms And Flooding | Sep 22, 2010 |
| Flooding | Mar 1, 2010 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
64 since 1996: 27 flash floods and 37 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | Jul 18, 2025 | — |
| Flood | Aug 17, 2025 | — |
| Flash Flood | Aug 17, 2025 | — |
| Flood | Jun 22, 2024 | — |
| Flash Flood | Jun 21, 2024 | — |
| Flood | Jun 21, 2024 | — |
| Flood | Apr 12, 2023 | — |
| Flood | Apr 11, 2023 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flash Flood · Jul 18, 2025. A cluster of thunderstorms developed north of U.S. Highway 14 near the South Dakota-Minnesota border during the evening of July 18. These thunderstorms drifted south and east along a slow-moving surface boundary and began to train/back-build across the Marshall, MN area. Four to eight inches of rain fell within 2 to 3 hours, resulting in significant flash flooding across the city, especially for areas south and ea…
Flood · Aug 17, 2025. During the overnight, a slow moving convective cluster within an environment with a strong low-level jet and abundant deep-layer moisture slid from western to southern Minnesota. Storms continually regenerated on the southwest flank of the cluster, with a boundary remaining stationary for several hours from south of Marshall to north of Westbrook. Some areas had more spotty heavy rainfall the prior night, and new…
Flash Flood · Aug 17, 2025. During the overnight, a slow moving convective cluster within an environment with a strong low-level jet and abundant deep-layer moisture slid from western to southern Minnesota. Storms continually regenerated on the southwest flank of the cluster, with a boundary remaining stationary for several hours from south of Marshall to north of Westbrook. Some areas had more spotty heavy rainfall the prior night, and new…
Flood · Jun 22, 2024. A multi-day significant heavy rainfall event from June 20-22 resulted in widespread rain totals between 5 and 10 inches across southwest Minnesota. As rainfall reached area streams and rivers, major to record flooding was observed, devastating multiple towns and communities. Extensive overland flooding also resulted in significant impacts and damages. All river crest information is preliminary until made official…
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 Lyon 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.