Dorchester County, SC
FEMA National Risk Index scores, disaster declarations & hazard data
Dorchester County has experienced 26 federally declared disasters since 1989, most recently Severe Winter Storm in 2026. Its overall natural hazard risk is rated Relatively Moderate — near the middle compared to other US counties.
Dorchester County's highest-rated hazards are earthquake, hurricane, and ice storm, with its top risk rated "Relatively Moderate" by FEMA's National Risk Index. Recorded storm events have increased 19% 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. Dorchester County has been designated in 26 declarations since 1989, covering 7 disaster types including hurricane (15), tropical storm (3), biological (2).
| Year | Type | Event name |
|---|---|---|
| 2026 | Winter Storm | Severe Winter Storm |
| 2024 | Tropical Storm | Tropical Storm Debby |
| 2024 | Tropical Storm | Hurricane Helene |
| 2024 | Tropical Storm | Hurricane Debby |
| 2023 | Hurricane | Hurricane Idalia |
| 2023 | Hurricane | Hurricane Ian |
| 2022 | Hurricane | Hurricane Ian |
| 2020 | Biological | Covid-19 Pandemic |
| 2020 | Biological | Covid-19 |
| 2019 | Hurricane | Hurricane Dorian |
Showing the 10 most recent of 26 total declarations since 1989.
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 | 79 | 0 | 0 | — |
| Inland Flooding | Relatively Moderate | 78.7 | 31 | 0 | $835K |
| Coastal Flooding | Relatively Low | 59.2 | 0 | 0 | — |
| Earthquake | Relatively Moderate | 97.9 | 5 | — | — |
| Heat Wave | Relatively Low | 69.2 | 0 | 0 | — |
| Tornado | Relatively Moderate | 74.8 | 4 | 0 | — |
| Hurricane | Relatively High | 97.9 | 0 | 0 | — |
| Hail | Relatively Low | 45.7 | 41 | 0 | — |
| Strong Wind | Relatively Low | 18.7 | 0 | 0 | — |
| Winter Weather | Relatively Moderate | 68 | 0 | 0 | — |
| Ice Storm | Relatively High | 83.4 | — | — | — |
| Cold Wave | Relatively Moderate | 67.9 | — | — | — |
| Lightning | Relatively High | 82.7 | 5 | 0 | $206K |
| Drought | Very Low | 27.7 | 0 | 0 | — |
| Landslide | Very Low | 14 | 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
Dorchester County ranks in the 63rd 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 | 63rd | Moderate |
| Socioeconomic status | 61st | Moderate |
| Household characteristics | 66th | Moderate |
| Racial & ethnic minority status | 76th | High |
| Housing type & transportation | 45th | Low |
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 | 68th | Relatively High |
| Risk to homes | 68th | Relatively High |
| Buildings in direct exposure zone | 51.9% | — |
NOAA tracked 81 weather events in this county over 2016–2025: 37 in 2016–20 vs 44 in 2021–25 (+19% — frequency increasing).
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 Dorchester County?
According to the FEMA National Risk Index, the highest-risk hazards in Dorchester County, South Carolina are earthquake, hurricane, and ice storm. The county's overall natural hazard risk is rated Relatively Moderate — near the middle compared to other US counties.
Has Dorchester County received federal disaster declarations?
Yes. Dorchester County has received 26 federal disaster declarations since 1989, including declarations in 2026. The most common disaster type on record is hurricane (15 declarations).
Has Dorchester County had any FEMA disaster declarations in 2024, 2025, or 2026?
Yes. Recent federal disaster declarations for Dorchester County include Severe Winter Storm (2026), Tropical Storm Debby (2024), Hurricane Helene (2024), Hurricane Debby (2024). See the declarations table above for the full history since 1989.
How does Dorchester County's natural hazard risk compare to nearby counties?
Among neighboring counties, Charleston County, SC has the highest overall natural hazard risk (Relatively High) and Bamberg County, SC has the lowest (Relatively Low). Dorchester County is rated Relatively Moderate overall.
How is Dorchester County's composite disaster risk index calculated?
Dorchester 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. Dorchester County's composite score of 94 means its overall natural hazard risk is higher than 94% of US counties.