County annual report · FIPS 17031
2018 Cook County, IL Power Outage Report
In 2018, customers in Cook County, IL went without power for an average of 2.2 hours, a total of 4.7M customer-hours (Illinois average 2.5 hours). That ranks 54th worst of 102 Illinois counties and 1779th of 2,798 nationally.
Compared with IL, the US and 2017
Coverage line is EAGLE-I's share of Illinois customers tracked each year.
Biggest outages in Cook 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 23, 2018 13:30 | December 7, 2018 08:30 | 13d 19h | 101,662 | 2.4M |
| 2 | May 1, 2018 10:00 | May 2, 2018 10:00 | 1d | 14,659 | 20K |
| 3 | October 18, 2018 08:00 | October 24, 2018 06:30 | 5d 22h | 12,824 | 96K |
| 4 | March 11, 2018 12:30 | March 12, 2018 03:30 | 15h | 12,278 | 22K |
| 5 | August 30, 2018 11:30 | September 11, 2018 09:30 | 11d 22h | 11,366 | 145K |
| 6 | August 23, 2018 10:30 | August 30, 2018 10:00 | 6d 23h | 10,122 | 136K |
| 7 | September 24, 2018 03:30 | October 1, 2018 05:30 | 7d 2h | 8,566 | 89K |
| 8 | July 1, 2018 11:00 | July 18, 2018 23:15 | 17d 12h | 8,454 | 209K |
| 9 | May 2, 2018 11:00 | May 4, 2018 09:00 | 1d 22h | 7,326 | 76K |
| 10 | June 13, 2018 09:00 | July 1, 2018 10:00 | 18d 1h | 5,613 | 191K |
Outage episodes by size in 2018: 161 reached 100+ customers, 92 reached 1,000+ customers, 6 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 Cook 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 |
|---|---|---|---|---|---|
| Commonwealth Edison Co | 2018 | 2.0 hrs | 0.82 | 58 min | 0.70 |
| Northern Indiana Pub Serv Co | - | - | - | - | - |
| University of Illinois | - | - | - | - | - |
| Village of Winnetka - (IL) | - | - | - | - | - |
About this data
- Outage figures come from DOE/ORNL EAGLE-I, which records customers out by county every 15 minutes. EAGLE-I tracked about 92% of Illinois's customers in 2018; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 2,162,007 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. Cook County has data for 2015–2025.
Cite this report
MassOutage (massoutage.com), Cook County, IL 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/illinois/cook-county