Chester County Power Outage History
2014–2025 · Pennsylvania
Worse than average — more frequent or longer outages than most counties. How grades are calculated
Outages by year
Outages by month (seasonality)
Worst outage events on record
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| Aug 4, 2020 | 131 hrs | 110,546 (41%) | Tropical Storm Isaias |
| Jul 17, 2024 | 94 hrs | 77,059 (29%) | Excessive Heat |
| Jun 23, 2015 | 20 hrs | 75,718 (28%) | Heat |
| Jun 3, 2020 | 129 hrs | 72,581 (27%) | Thunderstorm Wind |
| Jan 9, 2024 | 76 hrs | 65,902 (25%) | Winter Weather |
Over the 12 years from 2014 to 2025, Chester County recorded 4,216 distinct power outage events, averaging 2.2 hours per event.
The single worst outage on record in Chester County started August 4, 2020 (Tropical Storm Isaias), lasting 131 hours and leaving up to 110,546 customers without power (41% of the county) at its peak.
July has historically been the worst month for outages in Chester County, with 553 events recorded during that month across the dataset.
Based on this history, Chester County earns a Reliability Grade of D, placing it in the 23rd percentile nationally for grid reliability (higher percentile = more reliable).
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Similar counties in Pennsylvania
Counties with the closest reliability grade and national percentile to Chester County.
| County | Grade | National percentile |
|---|---|---|
| Armstrong County | D | 23rd |
| Perry County | D | 23rd |
| Venango County | D | 24th |
| Bucks County | D | 24th |
| Columbia County | D | 27th |
FAQ
How often does power go out in Chester County?
Between 2014 and 2025, Chester County recorded 4,216 outage events, averaging 2.2 hours each.
What is Chester County's reliability grade?
Chester County has a Reliability Grade of D, in the 23rd national percentile.
What was the worst power outage in Chester County?
The worst outage on record started August 4, 2020 (Tropical Storm Isaias), lasting 131 hours and affecting up to 110,546 customers.