Lyon County, Iowa
Natural disaster risk, federal disaster history and flood insurance facts.
Lyon County, Iowa has a very low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 81% of US counties. It ranks 86th of 99 counties in Iowa. The costliest hazards here are inland flooding, hail and tornadoes. FEMA estimates about $11 million a year in expected losses, or roughly $913 per resident. Since 1965 it has been included in 14 federal disaster or emergency declarations for natural events (12 major disasters). The most recent was in June 2024 (severe storms, flooding, straight-line winds and tornadoes). Only 39 homes here carry federal flood insurance. Since 1978, federal flood insurance has paid about $1.7 million on 75 claims here, including $1.1 million for floods in 2014.
FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.
Top risks in Lyon County
- 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.
- Ask about the roof age and any impact-rated shingles.
- Check your home policy for a separate wind and hail deductible.
- 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.
All 18 hazards
What the ratings mean ›| Hazard | Rating | Score | Expected loss a year | |
|---|---|---|---|---|
| Inland flooding | 19.6 | $4M | ||
| Hail | 89.4 | $3M | ||
| Tornado | 45.9 | $2M | ||
| Cold wave | 41.8 | $1M | ||
| Drought | 72.0 | $906K | ||
| Ice storm | 67.9 | $303K | ||
| Strong wind | 18.6 | $248K | ||
| Winter weather | 71.1 | $209K | ||
| Heat wave | 29.9 | $206K | ||
| Lightning | 9.2 | $47K | ||
| Wildfire | 28.4 | $20K | ||
| Earthquake | 7.5 | $11K | ||
| Landslide | 33.4 | $615 |
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 relatively high in FEMA's measures.
Federal disaster history
Recent disasters nationwide ›Declarations by decade
Federal declarations for natural events that included Lyon County. 2020s bar runs to November 2026.
By type
Most recent
Show all 14
Iowa also had 11 statewide declarations that did not name single counties.
Storm history since 1951
Tornado risk by county ›The National Weather Service has logged 446 storm reports in Lyon County since 1951, with 1 death and 2 injuries and about $38.1 million in reported damage. The strongest on record here was an F2 tornado on April 26, 1986.
Strongest tornadoes
| Date | Strength | Near | Hurt / killed |
|---|---|---|---|
| Apr 26, 1986 | F2 | – | 2 / 1 |
| Jul 6, 1978 | F2 | – | 0 / 0 |
| Apr 26, 1986 | F2 | – | 0 / 0 |
| May 7, 1993 | F2 | Larchwood | 0 / 0 |
| Jun 25, 2010 | EF2 | Little Rock | 0 / 0 |
Most damaging storms
| Date | Type | Near | Damage |
|---|---|---|---|
| Jun 20, 2024 | Flood | Beloit | $13M |
| Jun 12, 2001 | Flash Flood | George | $4M |
| Jun 1, 2019 | Flood | Beloit | $4M |
| Jun 15, 2014 | Flood | Rock Rapids | $3M |
| Apr 26, 1986 | Tornado | – | $3M |
| Jul 6, 1978 | Tornado | – | $3M |
Source: NOAA Storm Events Database, county-based reports through Jul 25, 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 Lyon County
Check your address flood zone ›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 Lyon County
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; 4,870 housing units.
Compare in Iowa
All 99 ›| Largest counties | Overall risk | Top hazard |
|---|---|---|
| Polk County | Inland flooding | |
| Linn County | Inland flooding | |
| Scott County | Inland flooding | |
| Johnson County | Tornado | |
| Black Hawk County | Inland flooding | |
| Woodbury County | Inland flooding | |
| Dallas County | Inland flooding | |
| Dubuque County | Inland flooding |
Neighboring counties
| County | Overall risk | Declarations |
|---|---|---|
| Minnehaha County, SD | 15 | |
| Lincoln County, SD | 15 | |
| Sioux County | 13 | |
| Nobles County, MN | 19 | |
| O'Brien County | 13 | |
| Rock County, MN | 14 | |
| Osceola County | 13 |
Common questions about Lyon County
What is the biggest natural hazard in Lyon County?
Inland flooding has the highest expected yearly losses in Lyon County, about $3.7 million a year in FEMA's estimate. Hail is second at $2.5 million.
How many federal disasters has Lyon County had?
Lyon County has been included in 14 federal disaster or emergency declarations for natural events since 1965, including 12 major disasters. The most recent was Severe Storms, Flooding, Straight-Line Winds, and Tornadoes in June 2024.
Is Lyon County a high-risk place to live?
Its overall rating is Very Low, 86th highest of 99 in Iowa. 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 Lyon County?
Standard home insurance does not cover flooding. About 1 in 143 homes in Lyon 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 Lyon County had?
NOAA records list 43 tornadoes in Lyon County since 1950. The strongest was an F2 tornado on April 26, 1986. The weather service has also logged 176 hail reports and 97 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.