Power outage history
Knox County Tennessee
4.6hours
without power for the average customer in a typical year, 2018–2025
37th most of 73 in Tennessee 30% 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 Knox'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 7.9 hours for the average customer. Hatched years have a thin record and are left out of the averages.
Knox, 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 |
|---|---|---|---|---|---|---|
| Aug 7, 2023 | Thunderstorms | 68,001 | 28% | 45 h | 23 h | 650k |
| May 27, 2017 | Thunderstorms | 44,151 | 18% | 24 h | 13 h | 328k |
| Dec 24, 2020 | Winter storm | 19,852 | 8% | 47 h | 14 h | 301k |
| Apr 1, 2023 | Windstorm | 27,000 | 11% | 15 h | 9.2 h | 165k |
| Mar 31, 2022 | No storm report | 25,953 | 11% | 20 h | 18 h | 159k |
| Sep 27, 2024 | Hurricane Helene | 18,919 | 8% | 25 h | 21 h | 154k |
| Mar 3, 2023 | Thunderstorms | 20,927 | 9% | 18 h | 16 h | 151k |
| May 17, 2025 | No storm report | 17,546 | 7% | 15 h | 16 h | 124k |
| Jul 8, 2016 | Thunderstorms | 19,660 | 8% | 17 h | 14 h | 115k |
| Jul 20, 2022 | Thunderstorms | 8,869 | 4% | 21 h | 26 h | 108k |
| Dec 24, 2022 | No storm report | 24,273 | 10% | 8.5 h | 4.8 h | 98k |
| Dec 18, 2025 | Thunderstorms | 19,649 | 8% | 13 h | 12 h | 96k |
| Nov 6, 2018 | Thunderstorms | 21,788 | 9% | 14 h | 11 h | 89k |
| Mar 29, 2020 | Thunderstorms | 19,389 | 8% | 12 h | 8.5 h | 83k |
| Jul 14, 2016 | Thunderstorms | 22,193 | 9% | 9.0 h | 8.2 h | 79k |
| Mar 25, 2023 | No storm report | 18,008 | 7% | 9.5 h | 8.2 h | 77k |
| Dec 11, 2021 | Thunderstorms | 21,078 | 9% | 8.2 h | 8.5 h | 70k |
| May 6, 2022 | Thunderstorms | 20,708 | 8% | 7.0 h | 5.8 h | 68k |
| Oct 31, 2019 | Thunderstorms | 21,114 | 9% | 12 h | 1.0 h | 63k |
| Aug 16, 2024 | Thunderstorms | 16,385 | 7% | 6.5 h | 6.5 h | 57k |
| Nov 18, 2017 | No storm report | 17,101 | 7% | 7.5 h | 8.5 h | 50k |
| Feb 16, 2025 | No storm report | 10,233 | 4% | 7.8 h | 7.2 h | 47k |
| Sep 4, 2025 | Thunderstorms | 12,212 | 5% | 6.0 h | 6.2 h | 46k |
| Mar 12, 2022 | Winter storm | 8,776 | 4% | 12 h | 15 h | 45k |
| Jun 26, 2018 | Thunderstorms | 16,489 | 7% | 6.0 h | 30 min | 43k |
| Jul 31, 2020 | Thunderstorms | 11,506 | 5% | 6.5 h | 7.5 h | 42k |
| Jun 25, 2023 | Thunderstorms | 9,243 | 4% | 9.2 h | 21 h | 41k |
| Dec 23, 2022 | Windstorm | 18,082 | 7% | 6.0 h | 3.8 h | 41k |
| Apr 5, 2017 | Thunderstorms | 11,332 | 5% | 6.2 h | 16 h | 36k |
| Jul 6, 2016 | Thunderstorms | 13,983 | 6% | 5.8 h | 6.8 h | 35k |
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 Knox from twelve hours before it began to its peak. Matching shows coincidence, not proof of cause.
- Thunderstorms 45%
- No storm on record 34%
- Winter storm 7.8%
- Windstorm 6.2%
- Tropical storm 4.4%
- Flooding 2.4%
Who keeps the lights on
Utilities serving Knox
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 |
|---|---|---|---|---|---|---|
| Knoxville Utilities Board | Municipal | 274 | 149 | 1.26 | 13.8 | 197k |
| City of Lenoir | Municipal | 157 | 157 | 1.57 | 12.8 | 63k |
| City of Clinton | Municipal | 159 | 118 | 1.97 | 13.7 | 26k |
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.
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 244,081 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 →