County annual report · FIPS 06109
2021 Tuolumne County, CA Power Outage Report
In 2021, customers in Tuolumne County, CA went without power for an average of 119.5 hours, a total of 2.8M customer-hours (California average 6.6 hours). That ranks 6th worst of 57 California counties and 56th of 2,974 nationally.
Compared with CA, the US and 2020
Coverage line is EAGLE-I's share of California customers tracked each year.
Biggest outages in Tuolumne County, 2021
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | August 26, 2021 13:15 | August 29, 2021 23:45 | 3d 10h | 37,001 | 182K |
| 2 | July 31, 2021 15:15 | August 2, 2021 23:15 | 2d 8h | 33,462 | 228K |
| 3 | March 6, 2021 12:00 | March 7, 2021 04:15 | 16h 15m | 33,447 | 156K |
| 4 | April 16, 2021 02:15 | April 16, 2021 15:00 | 12h 45m | 30,901 | 219K |
| 5 | May 16, 2021 01:15 | May 16, 2021 05:30 | 4h 15m | 27,401 | 82K |
| 6 | December 26, 2021 01:15 | December 31, 2021 00:15 | 4d 23h | 9,277 | 610K |
| 7 | January 19, 2021 10:00 | January 25, 2021 00:00 | 5d 14h | 7,690 | 369K |
| 8 | November 7, 2021 13:30 | November 8, 2021 00:45 | 11h 15m | 6,493 | 17K |
| 9 | January 26, 2021 20:30 | February 7, 2021 21:00 | 12d | 6,211 | 582K |
| 10 | October 24, 2021 06:30 | October 26, 2021 23:30 | 2d 17h | 5,241 | 46K |
Outage episodes by size in 2021: 102 reached 100+ customers, 29 reached 1,000+ customers, 5 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 2021, 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. | 2021 | 10.4 hrs | 1.84 | 3.6 hrs | 1.32 |
| Southern California Edison Co | 2021 | 3.0 hrs | 1.11 | 1.7 hrs | 0.96 |
| Turlock Irrigation District | 2021 | 1.8 hrs | 1.12 | 75 min | 0.88 |
| 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 95% of California's customers in 2021; 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, 2021, 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/2021/california/tuolumne-county