Williamson County Power Outage History
2014–2025 · Tennessee
Top 20% most reliable nationally — infrequent, short outages. How grades are calculated
Outages by year
Outages by month (seasonality)
Worst outage events on record
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| May 3, 2020 | 0 hrs | 12,540 (10%) | Thunderstorm Wind |
| May 3, 2020 | 1 hrs | 12,499 (10%) | Thunderstorm Wind |
| May 4, 2020 | 0 hrs | 12,179 (10%) | Thunderstorm Wind |
| May 4, 2020 | 2 hrs | 11,396 (9%) | Thunderstorm Wind |
| Jul 1, 2023 | 10 hrs | 11,340 (9%) | Thunderstorm Wind |
Over the 12 years from 2014 to 2025, Williamson County recorded 800 distinct power outage events, averaging 1.4 hours per event.
The single worst outage on record in Williamson County started May 3, 2020 (Thunderstorm Wind), lasting 0 hours and leaving up to 12,540 customers without power (10% of the county) at its peak.
June has historically been the worst month for outages in Williamson County, with 100 events recorded during that month across the dataset.
Based on this history, Williamson County earns a Reliability Grade of A, placing it in the 90th percentile nationally for grid reliability (higher percentile = more reliable).
Sized for Williamson County's outage profile
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Similar counties in Tennessee
Counties with the closest reliability grade and national percentile to Williamson County.
| County | Grade | National percentile |
|---|---|---|
| Hamblen County | A | 90th |
| Gibson County | A | 88th |
| Overton County | A | 88th |
| Hamilton County | A | 88th |
| Anderson County | A | 91st |
FAQ
How often does power go out in Williamson County?
Between 2014 and 2025, Williamson County recorded 800 outage events, averaging 1.4 hours each.
What is Williamson County's reliability grade?
Williamson County has a Reliability Grade of A, in the 90th national percentile.
What was the worst power outage in Williamson County?
The worst outage on record started May 3, 2020 (Thunderstorm Wind), lasting 0 hours and affecting up to 12,540 customers.