Charleston CountyPower Outage History
What this grade means
Better than average — fewer or shorter outages than most counties. This county's outage history is better than the national median: recorded outages are less frequent and/or shorter in duration than a typical US county experienced over the same 12-year period. It isn't in the top tier nationally, but its track record points to lower-than-average outage risk.
Outages by year
Outages by month (seasonality)
Worst outage events on record
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| Sep 4, 2019 | 98 hrs | 137,536 (25%) | Coastal Flood |
| Oct 7, 2016 | 20 hrs | 97,936 (18%) | Storm Surge/Tide |
| Oct 8, 2016 | 117 hrs | 79,454 (15%) | Storm Surge/Tide |
| Sep 30, 2022 | 52 hrs | 77,760 (14%) | Hurricane Ian |
| Sep 11, 2017 | 84 hrs | 62,562 (11%) | Coastal Flood |
Was There an Outage on a Specific Date?
Pick a date to see whether a power outage was recorded for Charleston County, South Carolina that day.
Over the 12 years from 2014 to 2025, Charleston County recorded 2,404 distinct power outage events, averaging 1.7 hours per event.
The single worst outage on record in Charleston County started September 4, 2019 (Coastal Flood), lasting 98 hours and leaving up to 137,536 customers without power (25% of the county) at its peak.
August has historically been the worst month for outages in Charleston County, with 282 events recorded during that month across the dataset.
Based on this history, Charleston County earns a Reliability Grade of B, placing it in the 69th percentile nationally for grid reliability (higher percentile = more reliable).
Similar counties in South Carolina
Counties with the closest reliability grade and national percentile to Charleston County.
| County | Grade | National percentile |
|---|---|---|
| Beaufort County | B | 69th |
| Barnwell County | B | 68th |
| Lancaster County | B | 68th |
| Georgetown County | B | 72nd |
| Lexington County | B | 67th |
Most reliable counties nationally
The top 3 counties nationally by reliability grade and percentile.
| County | State | Grade | National percentile |
|---|---|---|---|
| Clay County | South Dakota | A | 100th |
| Clearwater County | Minnesota | A | 99th |
| Limestone County | Alabama | A | 99th |
Least reliable counties nationally
The bottom 3 counties nationally by reliability grade and percentile.
| County | State | Grade | National percentile |
|---|---|---|---|
| Clay County | West Virginia | F | 0th |
| Lincoln County | West Virginia | F | 0th |
| Cameron Parish | Louisiana | F | 0th |
FAQ
How often does power go out in Charleston County?
Between 2014 and 2025, Charleston County recorded 2,404 outage events, averaging 1.7 hours each.
What is Charleston County's reliability grade?
Charleston County has a Reliability Grade of B, in the 69th national percentile.
What was the worst power outage in Charleston County?
The worst outage on record started September 4, 2019 (Coastal Flood), lasting 98 hours and affecting up to 137,536 customers.