Power outage history
Frederick County Maryland
2.6hours
without power for the average customer in a typical year, 2018–2025
16th most of 24 in Maryland 60% 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 Frederick's customers who were without power at that day's worst moment.
Year by year
Hours in the dark, per customer
2022 was the worst well-recorded year, at 3.5 hours for the average customer. Hatched years have a thin record and are left out of the averages.
Frederick, 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 |
|---|---|---|---|---|---|---|
| Mar 2, 2018 | Windstorm | 7,301 | 6% | 38 h | 37 h | 158k |
| Dec 23, 2022 | Winter storm | 7,541 | 6% | 28 h | 7.0 h | 133k |
| Nov 19, 2016 | No storm report | 7,320 | 6% | 11 h | 7.5 h | 44k |
| Oct 31, 2019 | Thunderstorms | 4,825 | 4% | 12 h | – | 36k |
| Apr 19, 2025 | Thunderstorms | 2,994 | 2% | 15 h | – | 31k |
| May 26, 2021 | Thunderstorms | 7,247 | 5% | 6.5 h | 4.8 h | 30k |
| Feb 7, 2020 | Tornadoes | 5,478 | 4% | 10 h | 11 h | 29k |
| Feb 2, 2015 | No storm report | 4,752 | 4% | 8.8 h | – | 26k |
| Feb 16, 2025 | Windstorm | 3,419 | 3% | 11 h | – | 24k |
| Jan 16, 2022 | Winter storm | 4,407 | 3% | 9.2 h | – | 23k |
| Aug 18, 2019 | Thunderstorms | 6,196 | 5% | 6.5 h | 5.2 h | 23k |
| Jul 21, 2019 | Thunderstorms | 5,674 | 4% | 7.2 h | 11 h | 22k |
| Aug 7, 2023 | Thunderstorms | 6,470 | 5% | 6.5 h | 18 h | 22k |
| Apr 30, 2021 | No storm report | 5,128 | 4% | 4.5 h | 3.2 h | 20k |
| May 31, 2015 | No storm report | 9,606 | 7% | 2.0 h | 1.8 h | 18k |
| Aug 23, 2020 | Thunderstorms | 6,917 | 5% | 4.0 h | 5.0 h | 18k |
| Mar 23, 2019 | No storm report | 2,277 | 2% | 7.8 h | – | 17k |
| Jun 1, 2015 | Thunderstorms | 3,478 | 3% | 4.8 h | – | 16k |
| Apr 1, 2023 | Windstorm | 6,308 | 5% | 5.0 h | 2.2 h | 15k |
| Jun 19, 2025 | Thunderstorms | 4,240 | 3% | 5.5 h | – | 14k |
| Aug 9, 2024 | Hurricane Debby | 5,705 | 4% | 3.2 h | 6.2 h | 14k |
| Apr 9, 2016 | No storm report | 8,627 | 7% | 1.8 h | 1.8 h | 13k |
| Jun 8, 2015 | Thunderstorms | 4,920 | 4% | 4.0 h | – | 13k |
| Feb 18, 2022 | No storm report | 3,317 | 3% | 3.5 h | – | 11k |
| Apr 25, 2015 | No storm report | 5,410 | 4% | 2.2 h | 3.0 h | 10k |
| Jun 18, 2015 | Thunderstorms | 8,410 | 6% | 1.2 h | 30 min | 9.9k |
| May 2, 2021 | No storm report | 5,492 | 4% | 1.8 h | 1.0 h | 9.6k |
| May 30, 2019 | Thunderstorms | 5,151 | 4% | 3.0 h | 3.8 h | 9.6k |
| May 14, 2025 | No storm report | 2,812 | 2% | 4.5 h | – | 9.5k |
| Jul 23, 2017 | No storm report | 4,352 | 3% | 2.5 h | – | 9.4k |
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 Frederick from twelve hours before it began to its peak. Matching shows coincidence, not proof of cause.
- No storm on record 33%
- Thunderstorms 27%
- Windstorm 18%
- Winter storm 15%
- Tornadoes 2.9%
- Tropical storm 2.3%
- Flooding 0.9%
Who keeps the lights on
Utilities serving Frederick
As each utility reports to the Energy Information Administration for its whole Maryland territory, not this county alone. Outage minutes include major storm days.
| Utility | Type | Outage min / yr | Excl. major storms | Outages / yr | Residential ¢/kWh | Customers |
|---|---|---|---|---|---|---|
| The Potomac Edison Company | Investor Owned | 399 | 174 | 1.30 | 15.4 | 259k |
| Thurmont Municipal Light Co | MD | – | – | – | – | 38k |
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
- Adams, PA 6.4 h
- Carroll 6.4 h
- Washington 3.5 h
- Montgomery 2.8 h
- Frederick (this county) 2.6 h
- Loudoun, VA 2.6 h
- Howard 2.3 h
- Franklin, PA 2.2 h
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 132,173 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 →