County annual report · FIPS 17199
2020 Williamson County, IL Power Outage Report
In 2020, customers in Williamson County, IL went without power for an average of 1.0 hours, a total of 36K customer-hours (Illinois average 5.9 hours). That ranks 93rd worst of 102 Illinois counties and 2652nd of 3,019 nationally.
Compared with IL, the US and 2019
Coverage line is EAGLE-I's share of Illinois customers tracked each year.
Biggest outages in Williamson 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 | July 20, 2020 13:30 | July 21, 2020 15:00 | 1d 1h | 2,263 | 5,610 |
| 2 | August 3, 2020 11:45 | August 3, 2020 22:30 | 10h 45m | 1,491 | 588 |
| 3 | June 12, 2020 06:15 | June 12, 2020 07:30 | 1h 15m | 1,489 | 1,861 |
| 4 | April 8, 2020 14:45 | April 8, 2020 16:15 | 1h 30m | 1,057 | 791 |
| 5 | June 6, 2020 20:15 | June 7, 2020 10:15 | 14h | 555 | 1,843 |
| 6 | July 12, 2020 13:30 | July 12, 2020 18:00 | 4h 30m | 550 | 712 |
| 7 | June 18, 2020 06:15 | June 18, 2020 06:45 | 30m | 542 | 271 |
| 8 | June 4, 2020 05:00 | June 4, 2020 07:45 | 2h 45m | 539 | 842 |
| 9 | April 23, 2020 17:30 | April 23, 2020 20:15 | 2h 45m | 523 | 138 |
| 10 | June 27, 2020 07:15 | June 27, 2020 16:45 | 9h 30m | 512 | 1,390 |
Outage episodes by size in 2020: 35 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 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 |
|---|---|---|---|---|---|
| Ameren Illinois Company | 2020 | 3.7 hrs | 1.04 | 1.7 hrs | 0.82 |
| Southeastern IL Elec Coop, Inc | 2020 | 2.8 hrs | 1.23 | 1.5 hrs | 0.99 |
| 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 94% of Illinois's customers in 2020; 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, 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/illinois/williamson-county