County annual report · FIPS 55055
2023 Jefferson County, WI Power Outage Report
In 2023, customers in Jefferson County, WI went without power for an average of 15.9 hours, a total of 549K customer-hours (Wisconsin average 3.4 hours). That ranks 2nd worst of 72 Wisconsin counties and 548th of 2,977 nationally.
Compared with WI, the US and 2022
Coverage line is EAGLE-I's share of Wisconsin customers tracked each year.
Biggest outages in Jefferson County, 2023
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | July 29, 2023 03:30 | August 1, 2023 04:15 | 3d | 12,904 | 437K |
| 2 | June 25, 2023 04:00 | June 26, 2023 20:30 | 1d 16h | 8,279 | 52K |
| 3 | August 11, 2023 19:30 | August 12, 2023 14:15 | 18h 45m | 3,787 | 6,166 |
| 4 | February 21, 2023 12:30 | February 21, 2023 23:15 | 10h 45m | 3,355 | 1,679 |
| 5 | July 24, 2023 00:45 | July 24, 2023 03:30 | 2h 45m | 2,260 | 4,655 |
| 6 | May 3, 2023 19:30 | May 3, 2023 23:00 | 3h 30m | 1,581 | 3,341 |
| 7 | October 23, 2023 13:15 | October 23, 2023 19:15 | 6h | 1,466 | 376 |
| 8 | May 31, 2023 16:30 | May 31, 2023 21:45 | 5h 15m | 1,300 | 2,284 |
| 9 | June 18, 2023 07:00 | June 18, 2023 17:15 | 10h 15m | 1,243 | 2,431 |
| 10 | January 27, 2023 07:45 | January 27, 2023 11:15 | 3h 30m | 1,123 | 1,985 |
Outage episodes by size in 2023: 50 reached 100+ customers, 11 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 Jefferson County reported on EIA Form 861 for 2023, 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 | 2023 | 4.5 hrs | 1.04 | 85 min | 0.68 |
| Adams-Columbia Electric Coop | 2023 | 3.8 hrs | 1.09 | 3.8 hrs | 1.09 |
| 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 2023; 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, 2023, 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/2023/wisconsin/jefferson-county