County annual report · FIPS 55133
2023 Waukesha County, WI Power Outage Report
In 2023, customers in Waukesha County, WI went without power for an average of 7.6 hours, a total of 1.1M customer-hours (Wisconsin average 3.4 hours). That ranks 9th worst of 72 Wisconsin counties and 1063rd 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 Waukesha 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 04:30 | August 1, 2023 13:45 | 3d 9h | 23,527 | 477K |
| 2 | June 25, 2023 03:00 | June 27, 2023 06:30 | 2d 3h | 17,105 | 225K |
| 3 | April 10, 2023 07:00 | April 10, 2023 09:15 | 2h 15m | 9,055 | 18K |
| 4 | March 10, 2023 06:30 | March 11, 2023 17:15 | 1d 10h | 8,655 | 53K |
| 5 | April 5, 2023 02:15 | April 6, 2023 01:00 | 22h 45m | 4,580 | 12K |
| 6 | October 13, 2023 15:30 | October 15, 2023 03:15 | 1d 11h | 3,499 | 36K |
| 7 | February 14, 2023 21:00 | February 15, 2023 00:00 | 3h | 3,486 | 2,335 |
| 8 | June 13, 2023 15:45 | June 14, 2023 19:00 | 1d 3h | 3,441 | 16K |
| 9 | May 15, 2023 12:15 | May 16, 2023 01:00 | 12h 45m | 3,356 | 6,832 |
| 10 | October 24, 2023 22:30 | October 25, 2023 08:00 | 9h 30m | 3,223 | 4,766 |
Outage episodes by size in 2023: 117 reached 100+ customers, 49 reached 1,000+ customers, 2 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 Waukesha 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 |
| Oconomowoc Utilities | - | - | - | - | - |
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 ÷ 143,177 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. Waukesha County has data for 2015–2025.
Cite this report
MassOutage (massoutage.com), Waukesha 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/waukesha-county