County annual report · FIPS 17199
2015 Williamson County, IL Power Outage Report
In 2015, customers in Williamson County, IL went without power for an average of 1.1 hours, a total of 39K customer-hours (Illinois average 2.3 hours). That ranks 73rd worst of 100 Illinois counties and 1712th of 2,484 nationally.
Compared with IL, the US
Coverage line is EAGLE-I's share of Illinois customers tracked each year.
Biggest outages in Williamson County, 2015
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | June 26, 2015 05:00 | June 26, 2015 15:00 | 10h | 5,033 | 6,634 |
| 2 | July 6, 2015 09:30 | July 6, 2015 14:30 | 5h | 4,455 | 2,737 |
| 3 | June 12, 2015 20:45 | June 15, 2015 13:30 | 2d 16h | 1,992 | 4,007 |
| 4 | May 30, 2015 19:45 | May 31, 2015 06:15 | 10h 30m | 1,089 | 2,351 |
| 5 | August 28, 2015 13:45 | August 28, 2015 14:00 | 15m | 875 | 219 |
| 6 | May 25, 2015 02:45 | May 25, 2015 17:30 | 14h 45m | 804 | 3,455 |
| 7 | June 21, 2015 04:00 | June 21, 2015 23:45 | 19h 45m | 663 | 1,357 |
| 8 | July 15, 2015 17:00 | July 15, 2015 23:15 | 6h 15m | 584 | 738 |
| 9 | August 10, 2015 20:30 | August 10, 2015 23:30 | 3h | 548 | 690 |
| 10 | September 27, 2015 12:00 | September 27, 2015 22:30 | 10h 30m | 482 | 879 |
Outage episodes by size in 2015: 23 reached 100+ customers, 4 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 Williamson County reported on EIA Form 861 for 2015, 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 |
|---|---|---|---|---|---|
| Ameren Illinois Company | 2015 | 5.9 hrs | 1.39 | 2.2 hrs | 1.04 |
| Southeastern IL Elec Coop, Inc | 2015 | 2.9 hrs | 1.58 | 2.7 hrs | 1.51 |
| Ameren | - | - | - | - | - |
| Egyptian Electric Coop Assn | - | - | - | - | - |
| Southern Illinois Elec Coop | - | - | - | - | - |
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 Illinois's customers in 2015; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 35,624 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. Williamson County has data for 2015–2025.
Cite this report
MassOutage (massoutage.com), Williamson County, IL annual power outage report, 2015, 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/2015/illinois/williamson-county