County annual report · FIPS 55133
2020 Waukesha County, WI Power Outage Report
In 2020, customers in Waukesha County, WI went without power for an average of 3.6 hours, a total of 513K customer-hours (Wisconsin average 1.8 hours). That ranks 14th worst of 72 Wisconsin counties and 1711th of 3,019 nationally.
Compared with WI, the US and 2019
Coverage line is EAGLE-I's share of Wisconsin customers tracked each year.
Biggest outages in Waukesha County, 2020
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 9, 2020 16:15 | August 11, 2020 08:45 | 1d 16h | 11,004 | 40K |
| 2 | November 10, 2020 17:45 | November 11, 2020 23:00 | 1d 5h | 9,727 | 55K |
| 3 | January 25, 2020 12:30 | January 26, 2020 01:45 | 13h 15m | 9,148 | 33K |
| 4 | October 31, 2020 15:45 | November 2, 2020 07:30 | 1d 15h | 6,496 | 14K |
| 5 | June 9, 2020 20:15 | June 11, 2020 04:45 | 1d 8h | 5,976 | 61K |
| 6 | February 13, 2020 17:00 | February 14, 2020 01:15 | 8h 15m | 5,583 | 1,418 |
| 7 | August 28, 2020 14:00 | August 29, 2020 09:30 | 19h 30m | 5,294 | 12K |
| 8 | April 20, 2020 23:00 | April 21, 2020 21:45 | 22h 45m | 3,792 | 19K |
| 9 | July 9, 2020 11:15 | July 11, 2020 16:30 | 2d 5h | 3,659 | 25K |
| 10 | July 7, 2020 20:30 | July 8, 2020 22:45 | 1d 2h | 3,231 | 15K |
Outage episodes by size in 2020: 131 reached 100+ customers, 54 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 Waukesha County reported on EIA Form 861 for 2020, 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 | 2020 | 2.3 hrs | 0.87 | 1.6 hrs | 0.70 |
| 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 84% of Wisconsin's customers in 2020; 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, 2020, 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/2020/wisconsin/waukesha-county