Power outage history
St. Mary's County Maryland
4.5hours
without power for the average customer in a typical year, 2018–2025
7th most of 24 in Maryland 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 St. Mary's'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 7.8 hours for the average customer. Hatched years have a thin record and are left out of the averages.
St. Mary's, 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 |
|---|---|---|---|---|---|---|
| Jan 3, 2022 | Winter storm | 14,054 | 25% | 2.3 d | 30 h | 238k |
| Mar 2, 2018 | Windstorm | 11,852 | 21% | 2.2 d | 24 h | 184k |
| Aug 4, 2020 | Hurricane Isaias | 10,173 | 18% | 25 h | 14 h | 92k |
| Oct 11, 2018 | Hurricane Michael | 9,464 | 17% | 19 h | 14 h | 78k |
| May 16, 2025 | Thunderstorms | 11,745 | 21% | 22 h | 10 h | 54k |
| Jul 29, 2023 | Thunderstorms | 6,238 | 11% | 20 h | 10 h | 45k |
| Feb 19, 2021 | Winter storm | 7,105 | 13% | 10 h | 5.8 h | 39k |
| Jul 12, 2022 | Thunderstorms | 8,280 | 15% | 13 h | 4.0 h | 37k |
| Jan 9, 2024 | No storm report | 4,771 | 9% | 17 h | 18 h | 24k |
| Jul 1, 2025 | Thunderstorms | 5,623 | 10% | 9.5 h | 9.0 h | 24k |
| Jun 26, 2024 | Thunderstorms | 3,040 | 5% | 14 h | 15 h | 16k |
| Feb 14, 2015 | Windstorm | 1,911 | 3% | 10 h | – | 13k |
| Apr 1, 2023 | No storm report | 2,593 | 5% | 5.8 h | – | 13k |
| May 8, 2021 | No storm report | 1,607 | 3% | 8.2 h | – | 12k |
| Oct 5, 2020 | No storm report | 1,328 | 2% | 9.2 h | – | 12k |
| Jun 14, 2025 | No storm report | 1,691 | 3% | 7.2 h | – | 11k |
| Feb 7, 2020 | Thunderstorms | 3,509 | 6% | 5.8 h | 6.5 h | 11k |
| Apr 3, 2016 | Windstorm | 2,979 | 5% | 6.2 h | 7.5 h | 10k |
| May 13, 2025 | No storm report | 1,359 | 2% | 8.0 h | – | 10k |
| Jun 30, 2024 | Thunderstorms | 2,447 | 4% | 5.8 h | – | 9.6k |
| Dec 23, 2022 | No storm report | 4,434 | 8% | 6.0 h | 48 min | 9.2k |
| Jul 25, 2022 | Flooding | 10,669 | 19% | 2.0 h | 1.8 h | 9.0k |
| Jun 17, 2019 | Thunderstorms | 2,189 | 4% | 6.5 h | – | 8.6k |
| Sep 22, 2023 | No storm report | 4,956 | 9% | 4.8 h | 2.0 h | 8.1k |
| Jun 20, 2015 | Thunderstorms | 2,759 | 5% | 6.5 h | – | 8.1k |
| Jul 14, 2021 | Thunderstorms | 2,292 | 4% | 6.0 h | – | 7.8k |
| Aug 10, 2021 | No storm report | 9,252 | 17% | 1.0 h | 2.2 h | 7.8k |
| Mar 7, 2024 | No storm report | 1,624 | 3% | 4.8 h | – | 7.7k |
| Mar 18, 2015 | No storm report | 1,546 | 3% | 5.0 h | – | 7.6k |
| Mar 14, 2017 | Winter storm | 2,561 | 5% | 5.5 h | – | 7.3k |
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 St. Mary's from twelve hours before it began to its peak. Matching shows coincidence, not proof of cause.
- No storm on record 32%
- Winter storm 20%
- Thunderstorms 18%
- Windstorm 13%
- Tropical storm 12%
- Flooding 3.3%
- Heat 0.9%
Who keeps the lights on
Utilities serving St. Mary's
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 |
|---|---|---|---|---|---|---|
| Southern Maryland Elec Coop Inc | Cooperative | 173 | 118 | 1.56 | 16.4 | 163k |
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 55,898 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 →