Walworth County, SD
FEMA National Risk Index scores, disaster declarations & hazard data
Walworth County has experienced 12 federally declared disasters since 1976, most recently Covid-19 in 2020. Its overall natural hazard risk is rated Very Low — among the lowest-risk counties in the country.
Walworth County's highest-rated hazards are cold wave, winter weather, and wildfire, with its top risk rated "Relatively Moderate" by FEMA's National Risk Index. Recorded storm events have decreased 70% over the past five years compared to the prior five-year period.
Past disasters & FEMA designations
A federal disaster declaration officially designates a county for FEMA disaster assistance. Walworth County has been designated in 12 declarations since 1976, covering 6 disaster types including flood (5), biological (2), severe storm (2).
| Year | Type | Event name |
|---|---|---|
| 2020 | Biological | Covid-19 Pandemic |
| 2020 | Biological | Covid-19 |
| 2019 | Flood | Severe Winter Storm, Snowstorm, And Flooding |
| 2019 | Flood | Severe Storms And Flooding |
| 2010 | Severe Storm | Severe Winter Storm |
| 2005 | Coastal Storm | Hurricane Katrina Evacuation |
| 1997 | Severe Storm | Severe Winter Storms And Blizzard Conditions |
| 1997 | Flood | Severe Flooding, Sever Winter Storms,Heavy Rains High Winds |
| 1995 | Snowstorm | Severe Winter Storms |
| 1995 | Flood | Flooding |
Showing the 10 most recent of 12 total declarations since 1976.
Source: FEMA OpenFEMA Disaster Declarations Summaries. A single disaster can produce more than one record per county. Data current through September 2026.
Risk by hazard type
| Hazard | Risk rating | Risk score | Recorded events | Deaths | Prop. damage |
|---|---|---|---|---|---|
| Wildfire | Relatively Low | 80.7 | 0 | 0 | — |
| Inland Flooding | Very Low | 34.8 | 7 | 0 | $3.3M |
| Coastal Flooding | Not Applicable | — | 0 | 0 | — |
| Earthquake | Very Low | 7 | 1 | — | — |
| Heat Wave | Very Low | 18.4 | 5 | 0 | — |
| Tornado | Relatively Low | 27.7 | 2 | 0 | — |
| Hurricane | Not Applicable | — | 0 | 0 | — |
| Hail | Relatively Low | 63.5 | 46 | 0 | — |
| Strong Wind | Relatively Low | 18.5 | 0 | 0 | — |
| Winter Weather | Relatively Moderate | 82.3 | 0 | 0 | — |
| Ice Storm | Very Low | 27 | — | — | — |
| Cold Wave | Relatively Moderate | 88.8 | — | — | — |
| Lightning | Very Low | 11.1 | 0 | 0 | — |
| Drought | Relatively Low | 41.8 | 0 | 0 | — |
| Landslide | Very Low | 4.2 | 0 | 0 | — |
| Avalanche | Not Applicable | — | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
| Volcanic Activity | Not Applicable | — | — | — | — |
Scores are 0–100 percentiles relative to all US counties — higher means more exposed, not that a disaster is likely this year. Event counts: NOAA Storm Events 2016–2026; earthquake counts from USGS ComCat (M3.0+, 1996–2026). See the methodology page for details.
Community vulnerability
Walworth County ranks in the 50th percentile (Moderate) for community vulnerability — a measure of how hard disaster impacts tend to hit residents. Higher vulnerability means more displacement, worse health outcomes, and slower recovery after a disaster.
| SVI theme | Percentile | Vulnerability level |
|---|---|---|
| Overall | 50th | Moderate |
| Socioeconomic status | 41st | Low |
| Household characteristics | 38th | Low |
| Racial & ethnic minority status | 54th | Moderate |
| Housing type & transportation | 67th | Moderate |
Source: CDC/ATSDR Social Vulnerability Index 2022. Percentiles compare counties nationally — higher means more vulnerable relative to other counties. See CDC SVI for full methodology.
Future risk outlook
| Wildfire metric | National percentile | Level |
|---|---|---|
| Burn probability | 63rd | Relatively High |
| Risk to homes | 72nd | Relatively High |
| Buildings in direct exposure zone | 49.1% | — |
NOAA tracked 60 weather events in this county over 2016–2025: 46 in 2016–20 vs 14 in 2021–25 (-70% — frequency decreasing).
Wildfire: USDA Forest Service Wildfire Risk to Communities (RDS-2020-0016-2) — modeled values, not annual forecasts. See wildfirerisk.org. Inland flood and heat projections pending data availability; coastal sea-level projections are available for select coastal counties below — see the data page.
Nearby counties
Frequently asked questions
What natural hazards pose the greatest risk in Walworth County?
According to the FEMA National Risk Index, the highest-risk hazards in Walworth County, South Dakota are cold wave, winter weather, and wildfire. The county's overall natural hazard risk is rated Very Low — among the lowest-risk counties in the country.
Has Walworth County received federal disaster declarations?
Yes. Walworth County has received 12 federal disaster declarations since 1976, including declarations in 2020. The most common disaster type on record is flood (5 declarations).
Has Walworth County had any FEMA disaster declarations in 2024, 2025, or 2026?
No federal disaster declarations have been recorded for Walworth County since the start of 2024. Its most recent declaration on record is Covid-19 in 2020.
How does Walworth County's natural hazard risk compare to nearby counties?
Among neighboring counties, Dewey County, SD has the highest overall natural hazard risk (Relatively Low) and Campbell County, SD has the lowest (Very Low). Walworth County is rated Very Low overall.
How is Walworth County's composite disaster risk index calculated?
Walworth County's composite disaster risk index — officially FEMA's National Risk Index (NRI) — scores every US county on a 0–100 percentile scale across 18 natural hazard types, factoring in expected annual loss, social vulnerability, and community resilience. Walworth County's composite score of 40 means its overall natural hazard risk is higher than 40% of US counties.