County annual report · FIPS 17163
2021 St. Clair County, IL Power Outage Report
In 2021, customers in St. Clair County, IL went without power for an average of 3.8 hours, a total of 361K customer-hours (Illinois average 2.3 hours). That ranks 31st worst of 102 Illinois counties and 1584th of 2,974 nationally.
Compared with IL, the US and 2020
Coverage line is EAGLE-I's share of Illinois customers tracked each year.
Biggest outages in St. Clair County, 2021
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | October 25, 2021 02:45 | October 26, 2021 04:15 | 1d 1h | 28,422 | 72K |
| 2 | August 12, 2021 13:30 | August 16, 2021 23:00 | 4d 9h | 5,221 | 59K |
| 3 | August 23, 2021 12:15 | August 27, 2021 15:15 | 4d 3h | 5,202 | 28K |
| 4 | November 10, 2021 14:45 | November 15, 2021 18:15 | 5d 3h | 3,785 | 13K |
| 5 | October 15, 2021 12:30 | October 16, 2021 04:00 | 15h 30m | 3,302 | 5,061 |
| 6 | February 27, 2021 09:00 | February 28, 2021 04:30 | 19h 30m | 3,113 | 5,595 |
| 7 | July 29, 2021 16:15 | July 30, 2021 02:45 | 10h 30m | 2,773 | 2,289 |
| 8 | August 28, 2021 20:00 | September 2, 2021 19:45 | 4d 23h | 2,745 | 7,398 |
| 9 | April 8, 2021 14:00 | April 8, 2021 19:30 | 5h 30m | 2,469 | 4,445 |
| 10 | July 7, 2021 01:00 | July 7, 2021 08:15 | 7h 15m | 2,451 | 5,642 |
Outage episodes by size in 2021: 103 reached 100+ customers, 24 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 St. Clair County reported on EIA Form 861 for 2021, 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 | 2021 | 3.2 hrs | 1.11 | 2.0 hrs | 0.88 |
| Southwestern Electric Coop Inc - (IL) | 2021 | 3.9 hrs | 2.53 | 3.8 hrs | 2.48 |
| Tri-County Electric Coop, Inc (IL) | 2021 | 3.5 hrs | 1.86 | 63 min | 1.09 |
| Monroe County Elec Coop, Inc | 2018 | 1.6 hrs | 0.84 | 1.6 hrs | 0.84 |
| Ameren | - | - | - | - | - |
| Egyptian Electric Coop Assn | - | - | - | - | - |
| Clinton County Elec Coop, Inc | - | - | - | - | - |
| City of Highland | - | - | - | - | - |
| City of Mascoutah - (IL) | - | - | - | - | - |
| Village of Freeburg - (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 98% of Illinois's customers in 2021; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 94,355 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. St. Clair County has data for 2015–2025.
Cite this report
MassOutage (massoutage.com), St. Clair County, IL annual power outage report, 2021, 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/2021/illinois/st-clair-county