Enter any address in Lyon County, Minnesota to see its FEMA flood zone
Flash flooding from heavy rainfall events characterizes Lyon County. Between 1993 and 2023, NOAA Storm Events data recorded 37 flood events and 27 flash flood events in the county. For example, August 2025 saw multiple flash flood and flood events attributed to slow-moving storm systems producing 2 to 4 inches of rainfall over several hours.
National Flood Insurance Program (NFIP) claims data indicates that properties in Zone A have experienced the most claims, with 33 claims averaging $2,133. Properties in Zone X have also seen claims, averaging $4,390, with an average water depth of 0.3 feet. Homes in Zone UNKNOWN had the highest average payout at $6,763. Residents in Zone A, Zone X, and Zone UNKNOWN should pay particular attention to flood risk.
Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.
22 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
Lyon County, Minnesota has recorded 64 flood-related events since 1996 according to NOAA's Storm Events Database, including 27 flash floods and 37 river or area floods. The county has received 18 federal disaster declarations, 7 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.
FEMA Disaster Declarations (1969–2022)
Source: OpenFEMA Disaster Declarations Summaries.
| Declaration | Type | Date |
|---|---|---|
| Severe Storms, Straight-line Winds, Tornadoes, And Flooding | Severe Storm | May 29, 2022 |
| Covid-19 | Biological | Jan 20, 2020 |
| Covid-19 Pandemic | Biological | Jan 20, 2020 |
| Severe Winter Storm, Straight-line Winds, And Flooding | Flood | Mar 12, 2019 |
| Severe Storms, Tornadoes, Straight-line Winds, And Flooding | Flood | Jun 15, 2018 |
| Severe Storms, Straight-line Winds, Flooding, Landslides, And Mudslides | Flood | Jun 11, 2014 |
| Severe Storms, Flooding, And Tornadoes | Severe Storm | Jul 1, 2011 |
| Severe Storms And Flooding | Flood | Mar 16, 2011 |
| Severe Storms And Flooding | Severe Storm | Sep 22, 2010 |
| Flooding | Flood | Mar 1, 2010 |
NOAA Storm Events Database (1996–2025)
Source: NOAA National Weather Service Storm Events Database.
| Type | Date | Damage |
|---|---|---|
| Flash Flood | Jul 18, 2025 | 0.00K |
| Flood | Aug 17, 2025 | 0.00K |
| Flash Flood | Aug 17, 2025 | 0.00K |
| Flood | Jun 22, 2024 | 0.00K |
| Flash Flood | Jun 21, 2024 | 0.00K |
| Flood | Jun 21, 2024 | 0.00K |
| Flood | Apr 12, 2023 | 0.00K |
| Flood | Apr 11, 2023 | 0.00K |
| Flood | May 12, 2022 | 0.00K |
| Flood | Mar 8, 2020 | 0.00K |
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 fo...
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 p...
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 p...
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 ...
Flash Flood — Jun 21, 2024
A second mesoscale convective system in as many nights developed across southeast South Dakota and southwest Minnesota in the late afternoon and early evening in response to a weak mid-level wave and warm advection over a stalled frontal boundary to the south. Rainfall rates up to 2 to 3 inches per hour on top of previously saturated soil resulted in local flash flooding.
Source: NOAA National Weather Service Storm Events Database.
Source: OpenFEMA NFIP Individual Claims (2.25M records analyzed).
FEMA assigns flood zone designations to areas in Lyon County, Minnesota:
AE High Risk — 1% annual chance of flooding. Insurance required.
VE Very High Risk — Coastal flooding with wave action.
X (Shaded) Moderate Risk — 500-year floodplain.
X Low Risk — Outside major floodplains.
Properties in Lyon County, Minnesota that are in FEMA-designated Special Flood Hazard Areas (zones A and V) with federally backed mortgages are required to carry flood insurance.
Even outside high-risk zones, flood insurance is recommended. From 2014 to 2024, nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area.
Visit FloodSmart.gov to find an agent and get a quote.