Natural disaster risk in Walworth County, South Dakota
South Dakota · population 5,315 · FIPS 46129
Overall: very low risk
Walworth County has a composite risk score of 39.5 out of 100 — higher than 39% of US counties. It ranks 17 of 66 in South Dakota (1 = highest risk). Its highest-rated hazards are cold wave, winter weather, wildfire.
Drought now: Yes: D2 Severe Drought, 13 weeks
Yes. On the U.S. Drought Monitor map valid 13 October 2026, 25.12% of Walworth County is in D2 Severe Drought. Some of it has been at D2 or worse for 13 weeks in a row. In all, 60.69% of the county is in drought (D1 to D4).
Drought in Walworth County: the last 52 weeks · droughtmonitor.unl.edu
The U.S. Drought Monitor is jointly produced by the National Drought Mitigation Center at the University of Nebraska-Lincoln, the United States Department of Agriculture, the National Oceanic and Atmospheric Administration and the National Aeronautics and Space Administration. Map courtesy of NDMC.
Risk, loss, vulnerability and resilience
| Measure | Rating and score |
|---|---|
| Overall risk Expected annual loss, adjusted for social vulnerability and community resilience. |
Very low 39.5 |
| Expected annual loss About $10.2 million a year, on average, across all 18 hazards. |
Very low 35.9 |
| Social vulnerability Higher means people may find it harder to prepare and recover. |
Relatively high 66 |
| Community resilience Higher means a stronger ability to prepare, adapt and recover. |
Very high 82.3 |
Risk by hazard
FEMA's risk rating for each of 18 natural hazards in Walworth County, highest first. "Not applicable" means the hazard is not modelled here.
| Hazard | Risk rating and score |
|---|---|
| Cold wave | Relatively moderate 88 |
| Winter weather | Relatively moderate 82 |
| Wildfire | Relatively low 80 |
| Hail | Relatively low 63 |
| Drought | Relatively low 41 |
| Tornado | Relatively low 27 |
| Strong wind | Relatively low 18 |
| Inland (riverine) flooding | Very low 34 |
| Ice storm | Very low 26 |
| Heat wave | Very low 18 |
| Lightning | Very low 11 |
| Earthquake | Very low 6 |
| Landslide | Very low 4 |
| Avalanche | Not applicable |
| Coastal flooding | Not applicable |
| Hurricane | Not applicable |
| Tsunami | Not applicable |
| Volcanic activity | Not applicable |
FEMA disaster declarations for Walworth County
Federal declarations that designated Walworth County, since 1 Jan 2024 (the period this site keeps from OpenFEMA). Older declarations are in FEMA's own dataset.
Not since 1 Jan 2024: no FEMA disaster declaration in the records this site read names Walworth County.
All FEMA declarations in South Dakota, with estimated apply-by dates · Open FEMA deadlines
This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s). Dataset: Disaster Declarations Summaries - v2.
How to read these ratings
- Ratings run in five steps: very low, relatively low, relatively moderate, relatively high and very high. They compare a county with every other US county; they are not a measure of danger on their own.
- Scores run from 0 to 100 and are national percentiles. The bar shows the score: a score of 80 means a higher value than 80% of US counties.
- Overall risk combines the expected annual loss with social vulnerability and community resilience.
- Expected annual loss is the average yearly loss to buildings, people and agriculture the model expects from all 18 hazards.
- Social vulnerability describes how hard it may be for people to prepare for and recover from a disaster. Higher is worse.
- Community resilience describes a community's ability to prepare, adapt and recover. Higher is better.
- "Not applicable" means FEMA does not model that hazard there (for example, hurricanes far inland).
About this data
Source: FEMA National Risk Index, version 1.20, released December 2025, published by the Federal Emergency Management Agency (US public domain). About the National Risk Index. The index is a model of relative risk built from historical hazard records, what is exposed and community factors. It is not a forecast, it does not describe any single property, and it is not insurance or financial advice. For decisions about a specific address, check FEMA's flood maps and your local emergency management office.
Questions
What is the natural disaster risk in Walworth County, South Dakota?
FEMA's National Risk Index rates the overall risk in Walworth County as very low, with a score of 39.5 out of 100 (higher than 39% of US counties). That is a comparison with other US counties, not a forecast.
What are the biggest natural hazards in Walworth County?
The hazards rated highest for Walworth County are cold wave (relatively moderate), winter weather (relatively moderate), wildfire (relatively low).
What is the flood risk in Walworth County?
FEMA rates inland (river and rain) flooding risk in Walworth County as very low. For a specific property, check the FEMA flood map and your local floodplain office.
Has Walworth County had a FEMA disaster declaration?
Not since 1 Jan 2024: no FEMA disaster declaration in the records this site read names Walworth County.
Is Walworth County in a drought?
Yes. On the U.S. Drought Monitor map valid 13 October 2026, 25.12% of Walworth County is in D2 Severe Drought. Some of it has been at D2 or worse for 13 weeks in a row. In all, 60.69% of the county is in drought (D1 to D4).
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