County annual report · FIPS 55133
2018 Waukesha County, WI Power Outage Report
In 2018, customers in Waukesha County, WI went without power for an average of 2.3 hours, a total of 324K customer-hours (Wisconsin average 1.7 hours). That ranks 25th worst of 71 Wisconsin counties and 1742nd of 2,798 nationally.
Compared with WI, the US and 2017
Coverage line is EAGLE-I's share of Wisconsin customers tracked each year.
Biggest outages in Waukesha County, 2018
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | November 24, 2018 14:45 | November 25, 2018 01:15 | 10h 30m | 5,504 | 29K |
| 2 | January 27, 2018 14:45 | January 27, 2018 20:45 | 6h | 3,829 | 965 |
| 3 | July 1, 2018 12:45 | July 3, 2018 03:30 | 1d 14h | 3,448 | 17K |
| 4 | July 14, 2018 02:00 | July 15, 2018 00:00 | 22h | 3,176 | 6,948 |
| 5 | September 19, 2018 19:45 | September 19, 2018 21:00 | 1h 15m | 3,113 | 779 |
| 6 | July 30, 2018 20:00 | July 31, 2018 01:30 | 5h 30m | 2,928 | 1,646 |
| 7 | August 26, 2018 23:15 | August 28, 2018 21:00 | 1d 21h | 2,812 | 25K |
| 8 | June 15, 2018 10:15 | June 15, 2018 16:45 | 6h 30m | 2,763 | 5,694 |
| 9 | June 10, 2018 10:15 | June 10, 2018 18:00 | 7h 45m | 2,641 | 7,279 |
| 10 | May 3, 2018 02:00 | May 4, 2018 07:15 | 1d 5h | 2,509 | 16K |
Outage episodes by size in 2018: 106 reached 100+ customers, 35 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 Waukesha County reported on EIA Form 861 for 2018, 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 | 2018 | 2.0 hrs | 0.73 | 70 min | 0.59 |
| 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 83% of Wisconsin's customers in 2018; 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, 2018, 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/2018/wisconsin/waukesha-county