County annual report · FIPS 47187
2025 Williamson County, TN Power Outage Report
In 2025, customers in Williamson County, TN went without power for an average of 1.1 hours, a total of 130K customer-hours (Tennessee average 4.3 hours). That ranks 63rd worst of 81 Tennessee counties and 2740th of 3,000 nationally.
Compared with TN, the US and 2024
Coverage line is EAGLE-I's share of Tennessee customers tracked each year.
Biggest outages in Williamson 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 5, 2025 23:30 | September 6, 2025 23:30 | 1d | 10,700 | 8,309 |
| 2 | April 5, 2025 20:30 | April 8, 2025 01:45 | 2d 5h | 5,165 | 10K |
| 3 | April 21, 2025 12:45 | April 21, 2025 15:00 | 2h 15m | 4,313 | 1,904 |
| 4 | August 7, 2025 13:30 | August 7, 2025 22:00 | 8h 30m | 4,233 | 1,151 |
| 5 | February 14, 2025 19:00 | February 17, 2025 03:00 | 2d 8h | 3,693 | 2,039 |
| 6 | June 10, 2025 05:15 | June 10, 2025 05:30 | 15m | 3,186 | 797 |
| 7 | April 3, 2025 07:15 | April 4, 2025 07:15 | 1d | 3,045 | 5,893 |
| 8 | March 26, 2025 13:15 | March 27, 2025 00:15 | 11h | 2,773 | 804 |
| 9 | August 8, 2025 06:30 | August 8, 2025 23:45 | 17h 15m | 2,496 | 6,158 |
| 10 | June 15, 2025 00:30 | June 15, 2025 07:00 | 6h 30m | 2,437 | 1,247 |
Outage episodes by size in 2025: 116 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 Williamson 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 |
|---|---|---|---|---|---|
| Duck River Elec Member Corp | 2024 | 4.6 hrs | 2.46 | 2.7 hrs | 2.08 |
| Middle Tennessee E M C | 2024 | 49 min | 0.93 | 42 min | 0.88 |
| City of Dickson | 2024 | 5.2 hrs | 3.39 | 4.8 hrs | 3.26 |
| Nashville Electric Service | 2024 | 0 min | 0.00 | 87 min | 1.01 |
| Columbia Power System - (TN) | 2024 | 2.9 hrs | 2.77 | 2.7 hrs | 2.53 |
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 Tennessee's customers in 2025; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 123,583 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. Williamson County has data for 2015–2025.
Cite this report
MassOutage (massoutage.com), Williamson County, TN 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/tennessee/williamson-county