riskbycounty
FEMA NRI 1.19.0Updated Nov 2023 · Coverage 2014–2023Methodology

Lyon County Disaster Risk

Lyon County, Iowa

FEMA Risk Rating

Very Low

National Percentile

19th

of 3,144 counties

State Rank

#86

of 99 (1 = highest risk)

Flood Risk

20th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Very Low

Higher than 20% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Very Low

Higher than 28% of US counties

Tornado

Tornado and severe thunderstorm risk

Relatively Low

Higher than 46% of US counties

Earthquake

Seismic activity and ground shaking risk

Very Low

Higher than 8% of US counties

Risk Overview

About Natural Disaster Risk in Lyon County, Iowa

Lyon County ranks among Iowa's safest

With a composite risk score of 19.18, Lyon County sits roughly half the state average of 39.68, earning a very low risk rating. This significant cushion places Lyon among the least hazard-prone counties in Iowa.

Iowa's lowest-risk county overall

Lyon County posts the state's lowest composite risk score, with only Louisa County (17.46) coming close. This exceptional safety profile reflects minimal exposure to tornadoes, flooding, and other major natural disasters that plague other parts of Iowa.

Safest in northwest Iowa by a wide margin

Lyon's 19.18 score significantly outpaces Marshall County (62.47) and most other neighboring counties, making it a notably safer location within the region. This geographic pocket of lower risk stands out in the tornado-prone landscape of northern Iowa.

Tornado risk your primary concern

Tornado risk of 45.93 is your highest hazard exposure, though still below state average. Flood risk of 19.62 and wildfire risk of 28.37 round out your secondary threats, all of which remain relatively modest.

Basic homeowners policy typically adequate

Your exceptional low-risk profile means standard homeowners insurance provides solid protection without costly add-ons for most properties. Verify wind and hail coverage is included to address tornado exposure, and maintain adequate replacement cost limits.

Source: FEMA National Risk Index · Narrative reviewed by Evan Brooks, Data Editor

Preparedness Guide

What to Prepare for in Lyon County

Top Hazards by Exposure

  1. #1
    TornadoPrepare
    46th percentile
  2. #2
    WildfirePrepare
    28th percentile
  3. #3
    FloodPrepare
    20th percentile

Source: FEMA National Risk Index v1.19.0 · Percentiles are national (3,144 counties)

Risk Advisory: Lyon County

Risk Verdict

At the 19th percentile nationally, Lyon County experiences relatively limited natural hazard pressure compared to most of the country. Lyon County's 19th percentile ranking is favorable, though every county carries at least one natural hazard worth knowing — reviewing the specific risks listed above helps households focus their preparedness where it matters most.

Hazard Breakdown

Tornado risk is Lyon County's dominant natural hazard, ranked at the 46th percentile nationally under FEMA's National Risk Index. Wildfire ranks second at the 28th percentile nationally. Additional tracked hazards include flood (20th percentile), earthquake (8th percentile).

Preparedness Context

Lyon County ranks at the 46th percentile nationally for tornado exposure. Unlike many slow-onset hazards, tornadoes in Lyon County can reach full intensity in minutes; a pre-practiced household shelter plan matters far more than stockpiled supplies. The secondary wildfire hazard at the 28th percentile nationally adds seasonal complexity to Lyon County's preparedness calendar, since wildfire and tornado risk often peak at different points in the year. Lyon County county emergency management typically publishes annual severe-weather preparedness guides tailored to local tornado patterns; households benefit from reviewing these before storm season begins each spring.

Regional Context

A composite score 20.5 points below the Iowa state average puts Lyon County in a better-than-typical position relative to neighboring counties.

Is your household prepared for Lyon County's hazards?

Review FEMA's county-specific preparedness checklists and emergency planning guides.

FEMA Ready Guide →

Frequently Asked Questions

What is the natural disaster risk in Lyon County, IA?
Lyon County has a FEMA National Risk Index rating of Very Low, placing it in the 19th percentile nationally out of 3,144 counties. This composite score reflects the county's overall exposure to natural hazards including floods, wildfires, tornadoes, earthquakes, and hurricanes, weighted by expected annual loss and social vulnerability.
What types of natural hazards affect Lyon County?
Lyon County is evaluated for five major natural hazard types: tornado (46th percentile), wildfire (28th percentile), flooding (20th percentile), earthquake (8th percentile). The highest-risk hazard is tornado at the 46th percentile nationally. These scores are derived from FEMA's National Risk Index, which analyzes expected annual loss, social vulnerability, and community resilience for each hazard type.
How does Lyon County risk compare to the Iowa average?
Lyon County's composite risk percentile is 19th, compared to the Iowa state average of 40th percentile. The state's overall risk rating is Very Low. This means Lyon County faces lower natural disaster risk than the typical county in Iowa.
Is Lyon County at risk for tornado?
Yes, Lyon County's tornado risk is at the 46th percentile nationally. This is below the national median, indicating relatively lower exposure. For flooding specifically, Lyon County is at the 20th percentile.
How is natural disaster risk measured?
FEMA's National Risk Index (NRI) calculates risk scores for 18 natural hazard types across all U.S. counties and census tracts. The composite score combines Expected Annual Loss (estimated dollar losses from each hazard), Social Vulnerability (demographic factors affecting disaster impact), and Community Resilience (ability to recover). Percentile scores rank each county against all 3,144 U.S. counties, and risk ratings range from Very Low to Very High.
Is Lyon County a safe place to live?
Lyon County's composite risk score of 19th percentile is below the Iowa state average of 40th percentile, indicating relatively lower exposure to natural hazards. However, no county is completely risk-free. The primary hazard type is tornado at the 46th percentile. Residents should still maintain emergency preparedness plans and appropriate insurance coverage.
By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor

Data Source

Risk data sourced from the FEMA National Risk Index (NRI). Risk scores are relative rankings (0–100) across all US counties — not absolute risk measures. Higher scores indicate higher relative risk compared to other counties.

Disclaimer: This data is informational only. It is not financial, insurance, or legal advice. Always consult a qualified professional before making insurance or real estate decisions.