Power outage history
Sumner County Tennessee
4.5hours
without power for the average customer in a typical year, 2018–2025
40th most of 73 in Tennessee 32% below the national median
Every day since 2015
Eleven years, one night at a time
Each cell is a day. The brighter it is, the larger the share of Sumner's customers who were without power at that day's worst moment.
Year by year
Hours in the dark, per customer
2023 was the worst well-recorded year, at 18 hours for the average customer. Hatched years have a thin record and are left out of the averages.
Sumner, hours without power per customer
The record
The biggest outages since 2015
Ranked by customer-hours lost: customers out multiplied by how long they stayed out. Times are local.
| Began | Storm | Peak out | Share | Lasted | 90% restored | Customer-hours |
|---|---|---|---|---|---|---|
| Dec 9, 2023 | Tornadoes | 35,732 | 42% | 3.3 d | 40 h | 807k |
| Mar 3, 2023 | Windstorm | 24,019 | 28% | 3.1 d | 36 h | 414k |
| Dec 11, 2021 | Tornadoes | 9,785 | 12% | 35 h | 29 h | 128k |
| Apr 5, 2025 | Thunderstorms | 9,303 | 11% | 17 h | 16 h | 80k |
| May 4, 2020 | No storm report | 8,262 | 10% | 17 h | 5.8 h | 77k |
| May 8, 2024 | Thunderstorms | 8,256 | 10% | 17 h | 15 h | 62k |
| Dec 24, 2022 | No storm report | 13,014 | 15% | 5.2 h | 4.2 h | 43k |
| Jul 20, 2023 | Thunderstorms | 7,288 | 9% | 12 h | 9.5 h | 38k |
| Jul 8, 2016 | Thunderstorms | 8,034 | 9% | 12 h | 12 h | 37k |
| Feb 16, 2015 | Winter storm | 5,202 | 6% | 14 h | 14 h | 33k |
| Dec 23, 2022 | Winter storm | 6,071 | 7% | 9.8 h | 4.0 h | 24k |
| Jun 21, 2019 | Thunderstorms | 2,566 | 3% | 14 h | – | 20k |
| May 27, 2015 | Thunderstorms | 7,572 | 9% | 4.5 h | 3.8 h | 19k |
| Aug 6, 2019 | Thunderstorms | 6,575 | 8% | 4.8 h | 3.8 h | 18k |
| Feb 26, 2023 | No storm report | 858 | 1% | 20 h | – | 17k |
| May 4, 2021 | Tornadoes | 4,928 | 6% | 6.8 h | 5.5 h | 17k |
| Dec 9, 2018 | Winter storm | 3,376 | 4% | 8.0 h | – | 14k |
| Dec 13, 2015 | No storm report | 2,764 | 3% | 6.8 h | – | 13k |
| Jun 30, 2023 | Thunderstorms | 3,455 | 4% | 7.2 h | – | 12k |
| Jun 26, 2019 | Flooding | 6,660 | 8% | 4.0 h | 2.8 h | 12k |
| May 3, 2020 | Thunderstorms | 4,954 | 6% | 4.5 h | 3.8 h | 11k |
| Jun 18, 2025 | Thunderstorms | 4,689 | 6% | 4.0 h | 3.8 h | 11k |
| Jun 15, 2016 | Thunderstorms | 5,028 | 6% | 4.8 h | 5.8 h | 11k |
| Jul 7, 2016 | Thunderstorms | 2,734 | 3% | 5.5 h | – | 11k |
| May 6, 2021 | No storm report | 4,428 | 5% | 2.8 h | 2.5 h | 9.4k |
| May 16, 2025 | Thunderstorms | 3,344 | 4% | 7.5 h | – | 9.3k |
| Sep 10, 2016 | Thunderstorms | 2,906 | 3% | 3.2 h | – | 9.3k |
| Jun 26, 2024 | No storm report | 1,393 | 2% | 7.2 h | – | 9.0k |
| May 17, 2015 | Thunderstorms | 1,699 | 2% | 8.8 h | – | 8.7k |
| May 20, 2024 | No storm report | 6,907 | 8% | 1.2 h | 30 min | 8.6k |
After the peak
How fast the lights come back
Each line is one major outage, from its peak. The amber line is the typical path.
When it happens
The outage clock
Customer-hours out by month (rings, January innermost) and local hour, 2018–2025.
What was happening
Weather behind the outages
Each outage is matched to NOAA storm reports for Sumner from twelve hours before it began to its peak. Matching shows coincidence, not proof of cause.
- Tornadoes 40%
- No storm on record 25%
- Windstorm 18%
- Thunderstorms 14%
- Winter storm 1.9%
- Flooding 0.6%
Who keeps the lights on
Utilities serving Sumner
As each utility reports to the Energy Information Administration for its whole Tennessee territory, not this county alone. Outage minutes include major storm days.
| Utility | Type | Outage min / yr | Excl. major storms | Outages / yr | Residential ¢/kWh | Customers |
|---|---|---|---|---|---|---|
| Nashville Electric Service | Municipal | 0 | 83 | 0.00 | 14.0 | 425k |
| Cumberland Elec Member Corp | Cooperative | 221 | 171 | 2.67 | 13.8 | 102k |
| Tri-County Elec Member Corp (TN) | Cooperative | 528 | 239 | 3.91 | 12.9 | 25k |
| City of Gallatin | Municipal | 49 | 23 | 0.53 | 12.8 | 24k |
EIA Form 861, latest year each utility reported. Outage minutes are SAIDI, the yearly minutes the average customer goes without power; outages a year are SAIFI.
Next door
Neighbouring counties
About these numbers
Notes
Outages come from the EAGLE-I record of utility outage maps collected every 15 minutes by Oak Ridge National Laboratory. Hours without power are customer-hours divided by the county's 85,061 electricity customers. Averages use well-covered years from 2018. Outages shorter than 15 minutes, and utilities that publish no outage map, are not in the record, so these figures understate the total. How every number is made →