Hamlin County, South Dakota Natural Disaster Risk
FEMA National Risk Index assessment · SD
Very LowComposite Risk Score
National percentile: 10th
Hamlin County faces very low composite natural disaster risk (NRI Risk Index score 10.0, 10th national percentile), driven primarily by ice storm and hail exposure. Expected annual loss across all 18 hazard types is $7M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Hamlin County at very low composite risk, with a National Risk Index score of 10.0 out of 100 — placing it in the 10th national percentile and among the lowest-risk counties in the country. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Most of Hamlin County's expected losses come from ice storm (freezing rain that coats surfaces in heavy, damaging ice) at Medium risk — $203K in expected annual loss and about 0.52 events per year; hail (ice stones from severe thunderstorms that damage property and crops) at Low risk — $489K in expected annual loss and about 4.34 events per year; and cold wave (prolonged spells of dangerously low temperatures) at Low risk — $1M in expected annual loss and about 12.74 events per year. Across all hazards, FEMA estimates $7M in expected annual loss for a population of 6K.
Beyond physical exposure, Hamlin County has a very low social vulnerability rating (how susceptible the population is to harm) and a high community resilience rating (its capacity to prepare for and recover from disasters). A less vulnerable population paired with strong resilience helps the community absorb and recover from events.
The county's disaster history tells the same story: Hamlin County has received 22 federal disaster declarations since 1969, including 9 for flood events and 7 for severe storm events. The most recent was Severe Winter Storms and Snowstorm (winter storm), declared in February 2023.
Among 66 South Dakota counties, Hamlin County ranks #46 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Ice Storm | Medium | 0.52 / yr | $203K |
| Hail | Low | 4.34 / yr | $489K |
| Cold Wave | Low | 12.74 / yr | $1M |
| Winter Weather | Low | 21.84 / yr | $90K |
| Wildfire | Very Low | 0.00 / yr | $60K |
| Strong Wind | Low | 3.09 / yr | $683K |
| Drought | Low | 4.43 / yr | $99K |
| Tornado | Low | 0.32 / yr | $980K |
| Heat Wave | Very Low | 3.00 / yr | $160K |
| Landslide | Very Low | 0.05 / yr | $147 |
| Riverine Flood | Very Low | 1.93 / yr | $3M |
| Earthquake | Very Low | 0.00 / yr | $12K |
| Lightning | Very Low | 33.83 / yr | $10K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Hamlin County has received 22 federal disaster declarations since 1969, most recently Severe Winter Storms and Snowstorm in February 2023. Most frequent causes: Flood (9), Severe Storm (7), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| February 2023 | Winter Storm | Severe Winter Storms and Snowstorm |
| June 2022 | Severe Storm | Severe Storm, Straight-Line Winds, Tornadoes, and Flooding |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| September 2019 | Flood | Severe Storms and Flooding |
| June 2019 | Flood | Severe Winter Storm, Snowstorm, and Flooding |
| February 2017 | Severe Storm | Severe Winter Storm |
| August 2013 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| May 2011 | Flood | Flooding |
| May 2010 | Flood | Flooding |
Showing the 10 most recent of 22 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Hamlin County?
Hamlin County has a composite FEMA National Risk Index score of 10.0 out of 100, placing it in the Very Low category and the 10th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Hamlin County?
The three highest-rated hazards are Ice Storm (Medium, $203K EAL), Hail (Low, $489K EAL), Cold Wave (Low, $1M EAL). These account for most of the county's expected annual losses.
How does Hamlin County compare to other South Dakota counties?
Hamlin County ranks #46 of 66 South Dakota counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Hamlin County had?
FEMA records 22 federal disaster declarations for Hamlin County since 1969, most often 9 for flood events and 7 for severe storm events. The most recent was Severe Winter Storms and Snowstorm, declared in February 2023.
What does Expected Annual Loss (EAL) mean?
EAL is FEMA's estimate of average annual dollar losses from natural hazards, calculated from historical event data and exposure models. Hamlin County's $7M EAL is a statistical average, not a guarantee for any specific year or address.