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

Des Moines County Disaster Risk

Des Moines County, Iowa

FEMA Risk Rating

Relatively Low

National Percentile

56th

of 3,144 counties

State Rank

#22

of 99 (1 = highest risk)

Flood Risk

56th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Relatively Low

Higher than 56% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Relatively Low

Higher than 43% of US counties

Tornado

Tornado and severe thunderstorm risk

Relatively Low

Higher than 69% of US counties

Earthquake

Seismic activity and ground shaking risk

Relatively Low

Higher than 57% of US counties

Hurricane

Tropical cyclone and hurricane risk

Very Low

Higher than 15% of US counties

Risk Overview

About Natural Disaster Risk in Des Moines County, Iowa

Des Moines County: Above-Average Risk Profile

Des Moines County's composite risk score of 55.79 places it "Relatively Low" but well above Iowa's state average of 39.68, driven by tornado (69.40) and flood (56.04) exposure. The county also faces notably elevated earthquake risk at 56.71—the highest among Des Moines's peer counties—creating a three-threat profile unusual in the state. This combination reflects Des Moines's location along the Mississippi River and proximity to seismic zones.

Upper-Middle Risk Tier with Unique Quake Exposure

Des Moines County ranks in the upper-middle range of Iowa's disaster risk landscape, distinguished by extremely high tornado exposure (69.40) and unusually elevated earthquake risk (56.71) for eastern Iowa. This earthquake risk substantially exceeds state norms and reflects Des Moines's proximity to historical seismic activity zones. The combination of tornado, flood, and earthquake threats creates a multifaceted risk environment few other Iowa counties face.

Quake Risk Sets Des Moines Apart Regionally

Des Moines County's earthquake score of 56.71 far exceeds neighboring Louisa, Jefferson, and Henry counties, creating a distinctive seismic vulnerability within the region. Tornado and flood risks align more closely with neighbors, but Des Moines's earthquake exposure is regionally exceptional. This elevated seismic risk, combined with strong tornado exposure, distinguishes Des Moines from surrounding counties.

Tornadoes, Earthquakes, and Floods Converge

Tornado risk at 69.40 ranks among Iowa's highest, requiring robust safe room preparation and active weather monitoring during severe weather season. Earthquake risk at 56.71 is exceptionally high for the region, making home seismic assessment and securing heavy furniture a practical priority. Flood risk at 56.04 reflects Mississippi River proximity and tributary exposure, affecting low-lying properties year-round.

Multi-Hazard Preparedness Is Critical

Secure your home's foundation and anchor heavy furniture to walls to mitigate earthquake damage, a priority no other nearby county faces with equal urgency. Install a basement safe room for tornado protection and maintain flood insurance if within a mapped flood zone. Review your homeowner's policy for earthquake coverage options—many require separate endorsements—and update your plan annually.

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

Preparedness Guide

What to Prepare for in Des Moines County

Top Hazards by Exposure

  1. #1
    TornadoPrepare
    69th percentile
  2. #2
    EarthquakePrepare
    57th percentile
  3. #3
    FloodPrepare
    56th percentile

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

Risk Advisory: Des Moines County

Risk Verdict

Natural hazard pressure in Des Moines County is below the national midpoint, with a composite score at the 56th percentile. Proactive emergency planning and awareness of the specific hazards driving Des Moines County's score can meaningfully reduce household risk.

Hazard Breakdown

Tornado risk is Des Moines County's dominant natural hazard, ranked at the 69th percentile nationally under FEMA's National Risk Index. Earthquake ranks second at the 57th percentile nationally. Additional tracked hazards include flood (56th percentile), wildfire (43th percentile), hurricane (15th percentile).

Preparedness Context

With tornado ranked at the 69th percentile nationally, Des Moines County sits in a high-exposure zone where the difference between outcomes often comes down to proximity to a reinforced interior shelter and seconds of warning time. Alongside tornado exposure, earthquake at the 57th percentile nationally means Des Moines County households face multi-hazard severe-weather seasons that benefit from a single integrated emergency plan covering both threats. For Des Moines County households, safe rooms certified to FEMA 320/361 standards offer the highest protection during a direct tornado hit; households without a safe room should locate the innermost lowest-floor room in their building and practice the route to it before storm season.

Regional Context

Des Moines County is 16.1 composite risk points above the Iowa average, indicating that residents face greater natural hazard exposure than most of their in-state neighbors.

Is your household prepared for Des Moines 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 Des Moines County, IA?
Des Moines County has a FEMA National Risk Index rating of Relatively Low, placing it in the 56th 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 Des Moines County?
Des Moines County is evaluated for five major natural hazard types: tornado (69th percentile), earthquake (57th percentile), flooding (56th percentile), wildfire (43th percentile), hurricane (15th percentile). The highest-risk hazard is tornado at the 69th 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 Des Moines County risk compare to the Iowa average?
Des Moines County's composite risk percentile is 56th, compared to the Iowa state average of 40th percentile. The state's overall risk rating is Very Low. This means Des Moines County faces higher natural disaster risk than the typical county in Iowa.
Is Des Moines County at risk for tornado?
Yes, Des Moines County's tornado risk is at the 69th percentile nationally. This is above the national median. For flooding specifically, Des Moines County is at the 56th 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.
Why is Des Moines County higher risk than average?
Des Moines County's composite risk score of 56th percentile is above the Iowa state average of 40th percentile. This elevated risk is driven by tornado exposure (69th percentile), along with earthquake and flooding risk. Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.
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.