Sumner County Power Outage History
2014–2025 · Tennessee
Average — typical outage frequency and duration nationally. How grades are calculated
Outages by year
Outages by month (seasonality)
Worst outage events on record
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| Dec 9, 2023 | 80 hrs | 35,732 (37%) | Drought |
| Mar 3, 2023 | 98 hrs | 24,019 (25%) | Thunderstorm Wind |
| Jan 10, 2024 | 0 hrs | 17,222 (18%) | Drought |
| Dec 24, 2022 | 15 hrs | 13,014 (13%) | Winter Storm Elliott |
| Dec 11, 2021 | 71 hrs | 9,785 (10%) | Thunderstorm Wind |
Over the 12 years from 2014 to 2025, Sumner County recorded 998 distinct power outage events, averaging 2.0 hours per event.
The single worst outage on record in Sumner County started December 9, 2023 (Drought), lasting 80 hours and leaving up to 35,732 customers without power (37% of the county) at its peak.
July has historically been the worst month for outages in Sumner County, with 142 events recorded during that month across the dataset.
Based on this history, Sumner County earns a Reliability Grade of C, placing it in the 59th percentile nationally for grid reliability (higher percentile = more reliable).
Sized for Sumner County's outage profile
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Similar counties in Tennessee
Counties with the closest reliability grade and national percentile to Sumner County.
| County | Grade | National percentile |
|---|---|---|
| Lake County | C | 58th |
| Rhea County | B | 62nd |
| Obion County | B | 62nd |
| Claiborne County | B | 63rd |
| Cocke County | B | 63rd |
FAQ
How often does power go out in Sumner County?
Between 2014 and 2025, Sumner County recorded 998 outage events, averaging 2.0 hours each.
What is Sumner County's reliability grade?
Sumner County has a Reliability Grade of C, in the 59th national percentile.
What was the worst power outage in Sumner County?
The worst outage on record started December 9, 2023 (Drought), lasting 80 hours and affecting up to 35,732 customers.