County annual report · FIPS 06109
2025 Tuolumne County, CA Power Outage Report
In 2025, customers in Tuolumne County, CA went without power for an average of 13.6 hours, a total of 320K customer-hours (California average 7.6 hours). That ranks 13th worst of 57 California counties and 569th of 3,000 nationally.
Compared with CA, the US and 2024
Coverage line is EAGLE-I's share of California customers tracked each year.
Biggest outages in Tuolumne County, 2025
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | September 2, 2025 14:00 | September 6, 2025 05:15 | 3d 15h | 10,027 | 50K |
| 2 | March 27, 2025 14:45 | March 27, 2025 20:45 | 6h | 4,482 | 1,887 |
| 3 | December 9, 2025 16:15 | December 10, 2025 07:30 | 15h 15m | 3,856 | 4,286 |
| 4 | December 24, 2025 06:15 | December 26, 2025 21:15 | 2d 15h | 3,847 | 13K |
| 5 | September 24, 2025 13:45 | September 26, 2025 07:00 | 1d 17h | 3,415 | 26K |
| 6 | August 27, 2025 15:15 | August 28, 2025 02:45 | 11h 30m | 2,995 | 1,820 |
| 7 | July 22, 2025 06:15 | July 23, 2025 03:00 | 20h 45m | 2,993 | 6,843 |
| 8 | November 5, 2025 14:45 | November 5, 2025 19:30 | 4h 45m | 2,889 | 2,173 |
| 9 | August 30, 2025 14:00 | August 30, 2025 17:45 | 3h 45m | 2,816 | 6,338 |
| 10 | June 24, 2025 07:45 | June 24, 2025 10:00 | 2h 15m | 2,692 | 4,136 |
Outage episodes by size in 2025: 127 reached 100+ customers, 29 reached 1,000+ customers, 1 reached 10,000+ customers.
Utility reliability filed with the EIA
SAIDI (average outage time per customer) and SAIFI (average interruptions per customer) that utilities serving Tuolumne County reported on EIA Form 861 for 2025, or their most recent earlier filing. Utility-wide figures, not county-specific.
| Utility | EIA year | SAIDI | SAIFI | SAIDI excl. major events | SAIFI excl. major events |
|---|---|---|---|---|---|
| Pacific Gas & Electric Co. | 2024 | 8.5 hrs | 2.15 | 4.6 hrs | 1.82 |
| Southern California Edison Co | 2024 | 2.6 hrs | 0.99 | 1.7 hrs | 0.90 |
| Turlock Irrigation District | 2024 | 74 min | 0.79 | 49 min | 0.52 |
| WAPA-- Western Area Power Administration | - | - | - | - | - |
| Tuolumne County Pub Power Agny | - | - | - | - | - |
About this data
- Outage figures come from DOE/ORNL EAGLE-I, which records customers out by county every 15 minutes. EAGLE-I tracked about n/a of California's customers in 2025; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 23,610 customers (ORNL modeled county customer count), including major storm days. It is comparable across counties but is not the SAIDI a utility files.
- An outage event is a continuous stretch with customers out; counts at 100, 1,000 and 10,000+ use its peak.
- Years loaded: 2015–2025. Tuolumne County has data for 2016–2025.
Cite this report
MassOutage (massoutage.com), Tuolumne County, CA annual power outage report, 2025, data as of Oct 3, 2026 02:41 UTC, sources: DOE EAGLE-I (https://eagle-i.doe.gov/); EAGLE-I modeled customer counts (MCC) (https://figshare.com/); EIA Form 861 (utility reliability) (https://www.eia.gov/electricity/data/eia861/). https://massoutage.com/reports/2025/california/tuolumne-county