Charleston County, SC
FEMA National Risk Index scores, disaster declarations & hazard data
Charleston County has experienced 27 federally declared disasters since 1977, most recently Severe Winter Storm in 2026. Its overall natural hazard risk is rated Relatively High — higher risk than most US counties.
Charleston County's highest-rated hazards are coastal flooding, hurricane, and earthquake, with its top risk rated "Very High" by FEMA's National Risk Index. Recorded storm events have increased 86% 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. Charleston County has been designated in 27 declarations since 1977, covering 8 disaster types including hurricane (16), severe storm (3), biological (2).
| Year | Type | Event name |
|---|---|---|
| 2026 | Winter Storm | Severe Winter Storm |
| 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 |
| 2019 | Hurricane | Hurricane Dorian |
Showing the 10 most recent of 27 total declarations since 1977.
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 Moderate | 93.9 | 0 | 0 | — |
| Inland Flooding | Relatively Moderate | 89.9 | 99 | 1 | $278K |
| Coastal Flooding | Very High | 99.8 | 0 | 0 | — |
| Earthquake | Relatively High | 98.8 | 4 | — | — |
| Heat Wave | Relatively Moderate | 82.7 | 0 | 0 | — |
| Tornado | Relatively Moderate | 71 | 20 | 0 | — |
| Hurricane | Very High | 99.6 | 0 | 0 | — |
| Hail | Relatively Low | 60.9 | 57 | 0 | — |
| Strong Wind | Relatively Moderate | 82.5 | 0 | 0 | — |
| Winter Weather | Relatively Moderate | 84.2 | 0 | 0 | — |
| Ice Storm | Relatively High | 94.5 | — | — | — |
| Cold Wave | Relatively Moderate | 87.1 | — | — | — |
| Lightning | Relatively High | 92.6 | 25 | 0 | $624K |
| Drought | Relatively Low | 35.4 | 0 | 0 | — |
| Landslide | Very Low | 37.7 | 0 | 0 | — |
| Avalanche | Not Applicable | — | — | — | — |
| Tsunami | Insufficient Data | — | — | — | — |
| 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
Charleston County ranks in the 43rd percentile (Low) 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 | 43rd | Low |
| Socioeconomic status | 42nd | Low |
| Household characteristics | 11th | Very low |
| Racial & ethnic minority status | 72nd | Moderate |
| Housing type & transportation | 62nd | 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 | 84th | Very High |
| Risk to homes | 88th | Very High |
| Buildings in direct exposure zone | 37.0% | — |
NOAA tracked 200 weather events in this county over 2016–2025: 70 in 2016–20 vs 130 in 2021–25 (+86% — 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.
Sea level & coastal flooding
Measured at the Charleston NOAA tide gauge, the nearest long-term station to Charleston County — not modeled, directly measured water levels.
Projected days per year of high-tide flooding, by NOAA's severity tiers based on how far water rises above the normal high tide: minor (road closures, stormwater backup — disruptive, not damaging), moderate (can damage homes and businesses), and major (threat to life and property, often requires evacuation).
| Decade | Minor | Moderate | Major |
|---|---|---|---|
| 2030 | 15 | 0 | 0 |
| 2050 | 70 | 5 | 0 |
| 2070 | 195 | 45 | 1 |
| 2100 | 360 | 320 | 105 |
Projected flood days per year under NOAA's intermediate emissions scenario — the 2022 interagency Sea Level Rise Technical Report, the same federal dataset commercial climate-risk products are built on. Low/high scenario range and monthly detail: NOAA Tides & Currents.
Nearby counties
Frequently asked questions
What natural hazards pose the greatest risk in Charleston County?
According to the FEMA National Risk Index, the highest-risk hazards in Charleston County, South Carolina are coastal flooding, hurricane, and earthquake. The county's overall natural hazard risk is rated Relatively High — higher risk than most US counties.
Has Charleston County received federal disaster declarations?
Yes. Charleston County has received 27 federal disaster declarations since 1977, including declarations in 2026. The most common disaster type on record is hurricane (16 declarations).
Has Charleston County had any FEMA disaster declarations in 2024, 2025, or 2026?
Yes. Recent federal disaster declarations for Charleston County include Severe Winter Storm (2026), Hurricane Helene (2024), Hurricane Debby (2024). See the declarations table above for the full history since 1977.
How does Charleston County's natural hazard risk compare to nearby counties?
Among neighboring counties, Beaufort County, SC has the highest overall natural hazard risk (Relatively High) and Williamsburg County, SC has the lowest (Relatively Moderate). Charleston County is rated Relatively High overall.
How is Charleston County's composite disaster risk index calculated?
Charleston 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. Charleston County's composite score of 99 means its overall natural hazard risk is higher than 99% of US counties.