County annual report · FIPS 55055
2025 Jefferson County, WI Power Outage Report
In 2025, customers in Jefferson County, WI went without power for an average of 5.4 hours, a total of 185K customer-hours (Wisconsin average 3.9 hours). That ranks 16th worst of 72 Wisconsin counties and 1414th of 3,000 nationally.
Compared with WI, the US and 2024
Coverage line is EAGLE-I's share of Wisconsin customers tracked each year.
Biggest outages in Jefferson 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 | March 15, 2025 01:00 | March 16, 2025 12:00 | 1d 11h | 7,953 | 32K |
| 2 | June 21, 2025 18:15 | June 22, 2025 16:45 | 22h 30m | 4,678 | 36K |
| 3 | July 31, 2025 14:30 | July 31, 2025 19:15 | 4h 45m | 4,452 | 6,148 |
| 4 | November 12, 2025 05:00 | November 12, 2025 11:00 | 6h | 4,413 | 9,591 |
| 5 | June 1, 2025 11:15 | June 1, 2025 14:30 | 3h 15m | 3,902 | 10K |
| 6 | September 18, 2025 10:30 | September 18, 2025 12:00 | 1h 30m | 3,063 | 4,592 |
| 7 | September 23, 2025 01:15 | September 23, 2025 08:00 | 6h 45m | 2,707 | 6,207 |
| 8 | August 16, 2025 17:45 | August 18, 2025 00:45 | 1d 7h | 2,410 | 11K |
| 9 | August 12, 2025 10:15 | August 12, 2025 22:15 | 12h | 2,258 | 7,023 |
| 10 | May 1, 2025 13:15 | May 1, 2025 15:00 | 1h 45m | 2,088 | 2,078 |
Outage episodes by size in 2025: 62 reached 100+ customers, 25 reached 1,000+ customers, 0 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 Jefferson 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 |
|---|---|---|---|---|---|
| Wisconsin Electric Power Co | 2024 | 4.9 hrs | 1.04 | 1.8 hrs | 0.74 |
| Adams-Columbia Electric Coop | 2024 | 2.3 hrs | 1.15 | 2.3 hrs | 1.15 |
| Wisconsin Power & Light Co | - | - | - | - | - |
| Jefferson Utilities | - | - | - | - | - |
| Lake Mills Light & Water | - | - | - | - | - |
| Waterloo Light & Water Comm | - | - | - | - | - |
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 Wisconsin's customers in 2025; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 34,512 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. Jefferson County has data for 2015–2025.
Cite this report
MassOutage (massoutage.com), Jefferson County, WI 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/wisconsin/jefferson-county