Power outage history
Calvert County Maryland
4.8hours
without power for the average customer in a typical year, 2018–2025
4th most of 24 in Maryland 26% 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 Calvert'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 9.5 hours for the average customer. Hatched years have a thin record and are left out of the averages.
Calvert, 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 | 12,581 | 32% | 2.9 d | 46 h | 257k |
| Mar 2, 2018 | Windstorm | 5,613 | 14% | 2.5 d | 2.0 d | 149k |
| Aug 4, 2020 | Hurricane Isaias | 11,675 | 30% | 32 h | 21 h | 138k |
| May 16, 2025 | Thunderstorms | 8,498 | 22% | 26 h | 20 h | 67k |
| Jan 9, 2024 | Flooding | 2,883 | 7% | 13 h | 7.5 h | 22k |
| Jul 29, 2023 | Heat | 3,680 | 9% | 10 h | 7.8 h | 21k |
| Jul 6, 2020 | No storm report | 8,457 | 21% | 6.5 h | 2.0 h | 20k |
| Feb 19, 2021 | Winter storm | 3,589 | 9% | 12 h | 4.5 h | 15k |
| Feb 7, 2020 | Thunderstorms | 4,048 | 10% | 8.0 h | 5.0 h | 14k |
| Jul 9, 2021 | Hurricane Elsa | 3,978 | 10% | 8.2 h | 6.0 h | 14k |
| Jun 25, 2025 | Thunderstorms | 2,639 | 7% | 11 h | 9.8 h | 13k |
| Apr 21, 2021 | No storm report | 4,525 | 11% | 4.5 h | 4.5 h | 13k |
| Feb 14, 2015 | Windstorm | 1,876 | 5% | 17 h | – | 12k |
| Sep 14, 2021 | No storm report | 8,069 | 20% | 1.5 h | 1.2 h | 12k |
| Oct 11, 2018 | Hurricane Michael | 2,923 | 7% | 9.0 h | 12 h | 12k |
| Dec 7, 2023 | No storm report | 7,592 | 19% | 2.2 h | 2.2 h | 11k |
| Feb 16, 2025 | No storm report | 1,709 | 4% | 9.0 h | – | 9.8k |
| Jun 23, 2015 | Thunderstorms | 5,860 | 15% | 3.2 h | 1.0 h | 9.5k |
| Apr 2, 2016 | Windstorm | 1,834 | 5% | 10 h | – | 9.4k |
| Apr 13, 2020 | Windstorm | 2,604 | 7% | 4.8 h | 6.5 h | 8.9k |
| Aug 9, 2020 | No storm report | 7,137 | 18% | 2.8 h | 1.2 h | 8.8k |
| Dec 13, 2022 | No storm report | 7,706 | 20% | 1.2 h | 1.2 h | 8.4k |
| Nov 1, 2020 | No storm report | 3,313 | 8% | 4.8 h | 4.5 h | 7.8k |
| Jul 31, 2024 | Thunderstorms | 1,583 | 4% | 5.5 h | – | 6.7k |
| Jul 21, 2018 | No storm report | 2,342 | 6% | 5.5 h | 5.2 h | 6.3k |
| Mar 8, 2025 | No storm report | 3,946 | 10% | 4.8 h | 2.5 h | 6.1k |
| Mar 14, 2020 | No storm report | 1,652 | 4% | 9.2 h | – | 6.0k |
| Aug 7, 2022 | No storm report | 7,505 | 19% | 1.0 h | 1.0 h | 5.8k |
| Jun 26, 2024 | Thunderstorms | 2,639 | 7% | 5.2 h | 5.2 h | 5.7k |
| May 16, 2022 | Thunderstorms | 2,129 | 5% | 6.8 h | 6.0 h | 5.4k |
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 Calvert from twelve hours before it began to its peak. Matching shows coincidence, not proof of cause.
- No storm on record 28%
- Winter storm 24%
- Tropical storm 15%
- Thunderstorms 14%
- Windstorm 14%
- Flooding 2.6%
- Heat 2.0%
Who keeps the lights on
Utilities serving Calvert
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 |
|---|---|---|---|---|---|---|
| Baltimore Gas & Electric Co | Investor Owned | 175 | 65 | 0.87 | 20.2 | 1.2M |
| 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.
Next door
Neighbouring counties
- Calvert (this county) 4.8 h
- St. Mary's 4.5 h
- Charles 4.3 h
- Prince George's 3.2 h
- Anne Arundel 3.1 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 39,458 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 →