Dorchester County, South Carolina

What hazards hit Dorchester County most?

The most frequent records are severe thunderstorm wind events: 507 since 1955. 49% of its severe thunderstorm wind events since 1955 fell in June and July. The rank column places the county among South Carolina's counties by days with a record per 1,000 square miles of land over each hazard's complete period.

Source: NOAA NCEI Storm Events Database (county and forecast-zone records attributed to the county; a zone record shows its own totals on each county it covers). Days: dates with at least one record of the hazard in the county. Ranks: days with a record per 1,000 square miles of land (Census Bureau 2024 Gazetteer), since 1950 for tornadoes, 1955 for hail and thunderstorm wind, 1996 for the rest.

How many tornadoes has Dorchester County had?

NOAA records 22 tornadoes in Dorchester County from 1958 to 2022, the strongest rated EF1, with 0 deaths and 4 injuries recorded in the county. A tornado that crossed a county line is counted in each county it touched, with the length of its path inside the county.

Counted as whole tornadoes rather than county records, the Storm Prediction Center's database holds 22 tornadoes whose track touched Dorchester County since 1950 (NOAA's county records number 22, the same count); along their whole tracks they killed 1 person, 0 of them in Dorchester County.

Map of the strongest tornado tracks in South Carolina.

Source: NOAA NCEI Storm Events Database, tornado records by county (path length in the county, maximum width); ratings as published: F scale before February 1, 2007, EF scale after. Whole-track figures: NOAA Storm Prediction Center tornado database (1950-2025). SPC severe weather database.

When was the last damaging storm in Dorchester County?

The most recent record with damage, injuries or deaths is the June 27, 2026 thunderstorm wind ($1,250 in damage in 2025 dollars).

Source: NOAA NCEI Storm Events Database; every record of 2025-2026 is listed, earlier ones when they caused deaths, injuries or $250,000 of damage (2025 dollars), and every tornado.

The deadliest and costliest records

A damage figure marked "step" is a record from before 1993: NOAA then filed damage by category, and the figure is the category as entered, in the dollars of that year, not an estimate of the loss.

Source: NOAA NCEI Storm Events Database: deaths and injuries direct and indirect; damage is property plus crops as estimated by the National Weather Service, converted to 2025 dollars.

Is it getting more frequent?

Records per decade for Dorchester County's most frequent hazards. Counts rose everywhere after 1996, when NOAA began recording every event type, so compare decades within a hazard's complete period only (the shaded cells come before it).

High wind and dust storms in the 2010s: 25 records against 7 in the decade before, 25 of them forecast-zone records. Cells marked z rose mostly through zone records. The local National Weather Service office files these once per forecast zone, so a change in how it draws its zones or splits a storm into records moves this count as much as the weather does; read it beside the Dorchester County days with a record above.

Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).

What time of year?

49% of its severe thunderstorm wind events since 1955 fell in June and July. The two busiest months are in violet.

Source: NOAA NCEI Storm Events Database, records by the month they began.

Federal disaster declarations for Dorchester County

FEMA's register lists 26 declarations that include Dorchester County: 12 major disasters, 14 emergencies and 0 fire management assistance declarations. Most were for hurricane (15) and tropical storm (3).

Source: FEMA OpenFEMA Disaster Declarations Summaries (v2), declarations through October 2, 2026; one declaration is counted once however many areas it names. OpenFEMA dataset page.

How many floods has Dorchester County had?

NOAA's Storm Events Database holds 74 flood or flash flood records for Dorchester County from 1996 to 2025, on 43 days, with 0 deaths. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), Dorchester County ranks 392nd of 2,942 U.S. counties.

The National Flood Insurance Program has paid $16.9 million on 779 claims filed in Dorchester County; the most in one year was 387 in 2015. Claims count insured losses only: uninsured flood damage is not in this file.

Source: FEMA OpenFEMA NFIP Redacted Claims, as of September 8, 2026; claims by year of loss, payments in the dollars of the year paid. OpenFEMA dataset page.

FEMA's modeled risk for Dorchester County

FEMA's National Risk Index rates Dorchester County Relatively Moderate overall, with an expected annual loss of $176 million. These are FEMA's model estimates of future loss from 18 hazards, not a count of what happened; they can differ from the record above.

Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.

Counties that share a border with Dorchester County

1. Charleston County 1,975
2. Colleton County 1,543
3. Berkeley County 1,119
4. Orangeburg County 989
5. Dorchester County 957

Source: U.S. Census Bureau county adjacency file; NOAA NCEI Storm Events Database, records since 1950. The Census Bureau's adjacency file.

Next

• Tornadoes in South CarolinaEvery South Carolina tornado since 1950 and the counties with the most per square mile
• Severe thunderstorm wind in South CarolinaThe state's severe thunderstorm wind events, by county, year and month
• The South Carolina recordEvery hazard in the state, its deadliest events and its federal declarations
• FEMA's risk rating for each hazard in Dorchester CountyThe hazard risk calculator: 18 hazards beside the county's record
• Download Dorchester County's FEMA declarations (CSV)26 rows: every declaration that named the county, for your own analysis