San Francisco 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 |
|---|---|---|---|
| Dec 20, 2025 | 64 hrs | 131,898 (37%) | Unnamed event |
| May 20, 2025 | 12 hrs | 123,469 (34%) | Unnamed event |
| Mar 21, 2023 | 20 hrs | 38,880 (11%) | Strong Wind |
| Sep 20, 2019 | 5 hrs | 26,468 (7%) | Unnamed event |
| Feb 4, 2024 | 54 hrs | 25,833 (7%) | Unnamed event |
Over the 8 years from 2018 to 2025, San Francisco County recorded 2,786 distinct power outage events, averaging 3.0 hours per event.
The single worst outage on record in San Francisco County started December 20, 2025, lasting 64 hours and leaving up to 131,898 customers without power (37% of the county) at its peak.
December has historically been the worst month for outages in San Francisco County, with 295 events recorded during that month across the dataset.
Based on this history, San Francisco County earns a Reliability Grade of B, placing it in the 73rd percentile nationally for grid reliability (higher percentile = more reliable).
Sized for San Francisco County's outage profile
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Outage-prep kit
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Similar counties in California
Counties with the closest reliability grade and national percentile to San Francisco County.
| County | Grade | National percentile |
|---|---|---|
| Imperial County | B | 75th |
| Modoc County | B | 75th |
| Fresno County | B | 71st |
| Merced County | B | 70th |
| Alameda County | B | 68th |
FAQ
How often does power go out in San Francisco County?
Between 2018 and 2025, San Francisco County recorded 2,786 outage events, averaging 3.0 hours each.
What is San Francisco County's reliability grade?
San Francisco County has a Reliability Grade of B, in the 73rd national percentile.
What was the worst power outage in San Francisco County?
The worst outage on record started December 20, 2025, lasting 64 hours and affecting up to 131,898 customers.