Alameda County Power Outage History
2018–2025 · California
Better than average — fewer or shorter 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 |
|---|---|---|---|
| Oct 27, 2019 | 5 hrs | 88,608 (12%) | Wildfire |
| Sep 16, 2022 | 8 hrs | 78,293 (10%) | Heat |
| Feb 24, 2022 | 2 hrs | 78,121 (10%) | Unnamed event |
| Oct 27, 2019 | 3 hrs | 76,765 (10%) | Wildfire |
| Sep 9, 2023 | 0 hrs | 75,396 (10%) | Unnamed event |
Over the 8 years from 2018 to 2025, Alameda County recorded 4,446 distinct power outage events, averaging 3.2 hours per event.
The single worst outage on record in Alameda County started October 27, 2019 (Wildfire), lasting 5 hours and leaving up to 88,608 customers without power (12% of the county) at its peak.
October has historically been the worst month for outages in Alameda County, with 449 events recorded during that month across the dataset.
Based on this history, Alameda County earns a Reliability Grade of B, placing it in the 68th percentile nationally for grid reliability (higher percentile = more reliable).
Sized for Alameda County's outage profile
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Similar counties in California
Counties with the closest reliability grade and national percentile to Alameda County.
| County | Grade | National percentile |
|---|---|---|
| San Joaquin County | B | 65th |
| Orange County | B | 65th |
| Merced County | B | 70th |
| Sutter County | B | 64th |
| Fresno County | B | 71st |
FAQ
How often does power go out in Alameda County?
Between 2018 and 2025, Alameda County recorded 4,446 outage events, averaging 3.2 hours each.
What is Alameda County's reliability grade?
Alameda County has a Reliability Grade of B, in the 68th national percentile.
What was the worst power outage in Alameda County?
The worst outage on record started October 27, 2019 (Wildfire), lasting 5 hours and affecting up to 88,608 customers.