Jefferson County Power Outage History
2015–2025 · Tennessee
Better than average — fewer or shorter outages than most counties. How grades are calculated
Outages by year
Outages by month (seasonality)
Worst outage events on record
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| Aug 7, 2023 | 16 hrs | 11,865 (30%) | Thunderstorm Wind |
| Nov 29, 2023 | 8 hrs | 9,721 (25%) | Unnamed event |
| Sep 27, 2024 | 4 hrs | 9,007 (23%) | Tropical Storm Helene |
| Dec 23, 2022 | 2 hrs | 8,634 (22%) | Winter Storm Elliott |
| Apr 1, 2023 | 23 hrs | 8,009 (20%) | Unnamed event |
Over the 11 years from 2015 to 2025, Jefferson County recorded 369 distinct power outage events, averaging 2.4 hours per event.
The single worst outage on record in Jefferson County started August 7, 2023 (Thunderstorm Wind), lasting 16 hours and leaving up to 11,865 customers without power (30% of the county) at its peak.
June has historically been the worst month for outages in Jefferson County, with 54 events recorded during that month across the dataset.
Based on this history, Jefferson County earns a Reliability Grade of B, placing it in the 70th percentile nationally for grid reliability (higher percentile = more reliable).
Sized for Jefferson County's outage profile
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Similar counties in Tennessee
Counties with the closest reliability grade and national percentile to Jefferson County.
| County | Grade | National percentile |
|---|---|---|
| Sequatchie County | B | 70th |
| Coffee County | B | 69th |
| Loudon County | B | 69th |
| Maury County | B | 68th |
| Haywood County | B | 72nd |
FAQ
How often does power go out in Jefferson County?
Between 2015 and 2025, Jefferson County recorded 369 outage events, averaging 2.4 hours each.
What is Jefferson County's reliability grade?
Jefferson County has a Reliability Grade of B, in the 70th national percentile.
What was the worst power outage in Jefferson County?
The worst outage on record started August 7, 2023 (Thunderstorm Wind), lasting 16 hours and affecting up to 11,865 customers.