Allegheny CountyPower Outage History
What this grade means
Average — typical outage frequency and duration nationally. This county sits in the middle of the national distribution — its outage frequency and duration over the past 12 years are close to the nationwide median, neither notably better nor worse than most other US counties. A typical amount of backup-power preparedness is reasonable here.
Outages by year
Outages by month (seasonality)
Worst outage events on record
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| Apr 29, 2025 | 218 hrs | 270,977 (41%) | Thunderstorm Wind |
| Jun 17, 2024 | 70 hrs | 84,962 (13%) | Thunderstorm Wind |
| Feb 24, 2019 | 105 hrs | 58,700 (9%) | Winter Weather |
| Dec 30, 2024 | 48 hrs | 55,570 (8%) | Unnamed event |
| Mar 25, 2023 | 54 hrs | 46,195 (7%) | Strong Wind |
Was There an Outage on a Specific Date?
Pick a date to see whether a power outage was recorded for Allegheny County, Pennsylvania that day.
Over the 12 years from 2014 to 2025, Allegheny County recorded 4,323 distinct power outage events, averaging 2.9 hours per event.
The single worst outage on record in Allegheny County started April 29, 2025 (Thunderstorm Wind), lasting 218 hours and leaving up to 270,977 customers without power (41% of the county) at its peak.
June has historically been the worst month for outages in Allegheny County, with 546 events recorded during that month across the dataset.
Based on this history, Allegheny County earns a Reliability Grade of C, placing it in the 42nd percentile nationally for grid reliability (higher percentile = more reliable).
Similar counties in Pennsylvania
Counties with the closest reliability grade and national percentile to Allegheny County.
| County | Grade | National percentile |
|---|---|---|
| Westmoreland County | C | 41st |
| Tioga County | C | 41st |
| Juniata County | C | 43rd |
| Beaver County | C | 41st |
| Fayette County | C | 41st |
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 Allegheny County?
Between 2014 and 2025, Allegheny County recorded 4,323 outage events, averaging 2.9 hours each.
What is Allegheny County's reliability grade?
Allegheny County has a Reliability Grade of C, in the 42nd national percentile.
What was the worst power outage in Allegheny County?
The worst outage on record started April 29, 2025 (Thunderstorm Wind), lasting 218 hours and affecting up to 270,977 customers.