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

Walworth County Disaster Risk

Walworth County, South Dakota

FEMA Risk Rating

Very Low

National Percentile

40th

of 3,144 counties

State Rank

#17

of 66 (1 = highest risk)

Flood Risk

35th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Very Low

Higher than 35% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Relatively Low

Higher than 81% of US counties

Tornado

Tornado and severe thunderstorm risk

Very Low

Higher than 28% of US counties

Earthquake

Seismic activity and ground shaking risk

Very Low

Higher than 7% of US counties

Risk Overview

About Natural Disaster Risk in Walworth County, South Dakota

Walworth County faces elevated disaster risks

Walworth County scores 39.50 on the composite risk scale, substantially above the national average and ranked as Very Low. This represents one of the higher-risk profiles in the county's region.

Walworth is South Dakota's riskiest profiled county

At 39.50, Walworth County ranks highest among the eight counties profiled and exceeds the state average of 26.84 by nearly 50 percent. It faces the most complex and compounded natural disaster exposure in this group.

Walworth leads the high-risk corridor

Walworth County's 39.50 surpasses all peer counties in this analysis, including Union (37.12), Todd (36.61), and Tripp (36.45). It represents the highest-risk area in a zone of elevated hazard exposure.

Wildfire and flood risks reign supreme

Wildfire risk leads at 80.69, with substantial flood exposure at 34.76 and moderate tornado risk (27.67) completing the hazard profile. Residents face particular vulnerability to fire and water-related disasters.

Build robust, layered insurance protection

Walworth County homeowners should invest in comprehensive coverage for fire, flood, wind, and hail—ideally through both standard and supplemental policies. Annual policy reviews and property improvements focused on fire mitigation are essential in this high-risk environment.

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

Preparedness Guide

What to Prepare for in Walworth County

Top Hazards by Exposure

  1. #1
    WildfirePrepare
    81th percentile
  2. #2
    FloodPrepare
    35th percentile
  3. #3
    TornadoPrepare
    28th percentile

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

Risk Advisory: Walworth County

Risk Verdict

Natural disaster exposure in Walworth County is lower than roughly three-quarters of U.S. counties, with a composite score at the 40th percentile. At the 40th percentile nationally, Walworth County's natural hazard profile is comparatively favorable — community resilience is reinforced when individual households maintain a reviewed emergency plan.

Hazard Breakdown

Wildfire risk is Walworth County's dominant natural hazard, ranked at the 81th percentile nationally under FEMA's National Risk Index. Flood ranks second at the 35th percentile nationally. Additional tracked hazards include tornado (28th percentile), earthquake (7th percentile).

Preparedness Context

At the 81th percentile nationally for wildfire, Walworth County residents should verify whether their insurance policy includes replacement cost coverage for structures and whether the insurer still writes new policies in this fire-risk zone. The county's flood exposure at the 35th percentile nationally complements the wildfire risk — saturating rain after burn scarring often triggers secondary flood and debris flow events. Local USFS or Cal Fire (where applicable) fire risk maps and seasonal Red Flag Warning alerts from the National Weather Service are two free resources Walworth County residents can use to stay ahead of rapidly changing wildfire conditions.

Regional Context

A composite score 12.7 points above the South Dakota state average puts Walworth County in a higher-risk category than most counties in the state.

Is your household prepared for Walworth 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 Walworth County, SD?
Walworth County has a FEMA National Risk Index rating of Very Low, placing it in the 40th 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 Walworth County?
Walworth County is evaluated for five major natural hazard types: wildfire (81th percentile), flooding (35th percentile), tornado (28th percentile), earthquake (7th percentile). The highest-risk hazard is wildfire at the 81th 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 Walworth County risk compare to the South Dakota average?
Walworth County's composite risk percentile is 40th, compared to the South Dakota state average of 27th percentile. The state's overall risk rating is Very Low. This means Walworth County faces higher natural disaster risk than the typical county in South Dakota.
Is Walworth County at risk for wildfire?
Yes, Walworth County's wildfire risk is at the 81th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Walworth County is at the 35th 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 Walworth County higher risk than average?
Walworth County's composite risk score of 40th percentile is above the South Dakota state average of 27th percentile. This elevated risk is driven by wildfire exposure (81th percentile). 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.