Power outage history
St. Tammany Parish Louisiana
18hours
without power for the average customer in a typical year, 2018–2025
43rd most of 63 in Louisiana 2.7× 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. Tammany's customers who were without power at that day's worst moment.
Year by year
Hours in the dark, per customer
2021 was the worst well-recorded year, at 4.1 days for the average customer. Hatched years have a thin record and are left out of the averages.
St. Tammany, 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 29, 2021 | Hurricane Ida | 130,114 | 79% | 11.6 d | 7.3 d | 16M |
| Oct 28, 2020 | Hurricane Zeta | 80,509 | 49% | 2.8 d | 31 h | 2.2M |
| Oct 26, 2019 | Tropical Storm Olga | 40,301 | 25% | 2.5 d | 43 h | 911k |
| Sep 11, 2024 | Hurricane Francine | 33,719 | 21% | 42 h | 13 h | 479k |
| Apr 10, 2024 | Tornadoes | 25,021 | 15% | 39 h | 6.2 h | 228k |
| May 17, 2024 | Thunderstorms | 21,775 | 13% | 15 h | 12 h | 148k |
| Apr 9, 2020 | Thunderstorms | 22,482 | 14% | 12 h | 9.0 h | 98k |
| Feb 16, 2025 | Thunderstorms | 9,456 | 6% | 12 h | 8.5 h | 76k |
| Feb 2, 2021 | No storm report | 3,657 | 2% | 17 h | – | 55k |
| Oct 9, 2020 | Hurricane Delta | 9,311 | 6% | 16 h | 14 h | 53k |
| May 6, 2023 | Thunderstorms | 10,209 | 6% | 6.2 h | 3.5 h | 52k |
| Jan 29, 2019 | No storm report | 19,418 | 12% | 3.8 h | 2.5 h | 49k |
| Aug 15, 2023 | Heat | 13,275 | 8% | 7.2 h | 5.0 h | 42k |
| Nov 1, 2018 | Thunderstorms | 12,363 | 8% | 8.8 h | 5.2 h | 42k |
| May 3, 2017 | Thunderstorms | 4,443 | 3% | 14 h | – | 38k |
| Apr 15, 2023 | Thunderstorms | 15,400 | 9% | 7.5 h | 4.5 h | 38k |
| Dec 27, 2018 | No storm report | 7,597 | 5% | 6.5 h | 6.0 h | 31k |
| Aug 17, 2024 | No storm report | 11,463 | 7% | 4.8 h | 3.8 h | 24k |
| Nov 6, 2015 | No storm report | 5,185 | 3% | 4.8 h | 5.0 h | 24k |
| Dec 8, 2017 | No storm report | 5,388 | 3% | 6.2 h | 11 h | 20k |
| Aug 22, 2025 | No storm report | 5,986 | 4% | 5.8 h | 2.5 h | 19k |
| Aug 20, 2020 | Thunderstorms | 11,587 | 7% | 3.2 h | 2.8 h | 19k |
| May 19, 2016 | Thunderstorms | 7,622 | 5% | 4.2 h | 5.0 h | 18k |
| Jan 9, 2024 | Flooding | 3,467 | 2% | 10 h | – | 18k |
| Mar 11, 2018 | Thunderstorms | 5,933 | 4% | 5.0 h | 3.5 h | 18k |
| Feb 16, 2021 | No storm report | 18,288 | 11% | 2.0 h | 1.5 h | 16k |
| Dec 19, 2023 | No storm report | 3,811 | 2% | 4.2 h | – | 16k |
| Jun 28, 2019 | No storm report | 8,697 | 5% | 3.2 h | 2.0 h | 16k |
| May 26, 2015 | Thunderstorms | 7,071 | 4% | 5.5 h | 2.5 h | 16k |
| Jul 18, 2024 | Thunderstorms | 6,433 | 4% | 3.5 h | 2.2 h | 15k |
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. Tammany from twelve hours before it began to its peak. Matching shows coincidence, not proof of cause.
- Tropical storm 92%
- No storm on record 3.5%
- Thunderstorms 2.9%
- Tornadoes 1.1%
Who keeps the lights on
Utilities serving St. Tammany
As each utility reports to the Energy Information Administration for its whole Louisiana territory, not this county alone. Outage minutes include major storm days.
| Utility | Type | Outage min / yr | Excl. major storms | Outages / yr | Residential ¢/kWh | Customers |
|---|---|---|---|---|---|---|
| Entergy Louisiana LLC | Investor Owned | 253 | 218 | 1.83 | 11.9 | 962k |
| Cleco Power LLC | Investor Owned | 212 | 146 | 2.26 | 14.3 | 253k |
| Washington-St Tammany E C, Inc | Cooperative | 511 | 484 | 5.20 | 11.0 | 51k |
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
- St. John the Baptist 52 h
- Tangipahoa 52 h
- Jefferson 40 h
- Orleans 29 h
- Washington 23 h
- St. Tammany (this county) 18 h
- Hancock, MS 8.7 h
- Pearl River, MS 7.2 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 164,188 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 →