St. Tammany ParishPower Outage History
What this grade means
Bottom 20% least reliable nationally — frequent and/or long outages. This county ranks in the least reliable fifth of all US counties in our dataset: some combination of frequent outages, long restoration times, or customers affected puts it near the bottom nationally. Backup power is worth prioritizing here rather than treating it as optional.
Outages by year
Outages by month (seasonality)
Worst outage events on record
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| Aug 29, 2021 | 292 hrs | 130,114 (79%) | Tropical Storm Ida |
| Oct 28, 2020 | 74 hrs | 80,509 (49%) | Unnamed event |
| Aug 29, 2021 | 12 hrs | 46,249 (28%) | Tropical Storm Ida |
| Oct 26, 2019 | 4 hrs | 40,301 (25%) | Unnamed event |
| Oct 26, 2019 | 61 hrs | 39,133 (24%) | Unnamed event |
Was There an Outage on a Specific Date?
Pick a date to see whether a power outage was recorded for St. Tammany Parish, Louisiana that day.
Over the 12 years from 2014 to 2025, St. Tammany Parish recorded 2,311 distinct power outage events, averaging 1.9 hours per event.
The single worst outage on record in St. Tammany Parish started August 29, 2021 (Tropical Storm Ida), lasting 292 hours and leaving up to 130,114 customers without power (79% of the county) at its peak.
July has historically been the worst month for outages in St. Tammany Parish, with 257 events recorded during that month across the dataset.
Based on this history, St. Tammany Parish earns a Reliability Grade of F, placing it in the 10th percentile nationally for grid reliability (higher percentile = more reliable).
Similar counties in Louisiana
Counties with the closest reliability grade and national percentile to St. Tammany Parish.
| County | Grade | National percentile |
|---|---|---|
| Concordia Parish | F | 10th |
| Washington Parish | F | 10th |
| Jefferson Davis Parish | F | 9th |
| Caddo Parish | F | 9th |
| Claiborne Parish | F | 8th |
Most reliable counties nationally
The top 3 counties nationally by reliability grade and percentile.
| County | State | Grade | National percentile |
|---|---|---|---|
| Clay County | South Dakota | A | 100th |
| Clearwater County | Minnesota | A | 99th |
| Limestone County | Alabama | A | 99th |
Least reliable counties nationally
The bottom 3 counties nationally by reliability grade and percentile.
| County | State | Grade | National percentile |
|---|---|---|---|
| Clay County | West Virginia | F | 0th |
| Lincoln County | West Virginia | F | 0th |
| Cameron Parish | Louisiana | F | 0th |
FAQ
How often does power go out in St. Tammany Parish?
Between 2014 and 2025, St. Tammany Parish recorded 2,311 outage events, averaging 1.9 hours each.
What is St. Tammany Parish's reliability grade?
St. Tammany Parish has a Reliability Grade of F, in the 10th national percentile.
What was the worst power outage in St. Tammany Parish?
The worst outage on record started August 29, 2021 (Tropical Storm Ida), lasting 292 hours and affecting up to 130,114 customers.