County annual report · FIPS 17125
2021 Mason County, IL Power Outage Report
In 2021, customers in Mason County, IL went without power for an average of 4.3 hours, a total of 21K customer-hours (Illinois average 2.3 hours). That ranks 27th worst of 102 Illinois counties and 1469th 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 Mason 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 | December 11, 2021 02:00 | December 11, 2021 19:45 | 17h 45m | 914 | 11K |
| 2 | July 10, 2021 20:00 | July 10, 2021 22:45 | 2h 45m | 454 | 1,136 |
| 3 | June 25, 2021 23:15 | June 26, 2021 09:45 | 10h 30m | 312 | 1,680 |
| 4 | January 1, 2021 15:15 | January 4, 2021 16:00 | 3d | 292 | 2,614 |
| 5 | January 24, 2021 16:45 | January 24, 2021 21:30 | 4h 45m | 217 | 246 |
| 6 | August 8, 2021 23:00 | August 9, 2021 01:15 | 2h 15m | 138 | 196 |
| 7 | January 15, 2021 01:15 | January 15, 2021 07:15 | 6h | 90 | 194 |
| 8 | September 26, 2021 12:45 | September 26, 2021 17:15 | 4h 30m | 69 | 152 |
| 9 | August 12, 2021 21:15 | August 13, 2021 01:45 | 4h 30m | 68 | 218 |
| 10 | July 10, 2021 03:30 | July 10, 2021 07:15 | 3h 45m | 59 | 120 |
Outage episodes by size in 2021: 6 reached 100+ customers, 0 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 Mason 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 |
| Menard Electric Coop | 2021 | 7.8 hrs | 2.83 | 2.8 hrs | 1.73 |
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 ÷ 4,847 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. Mason County has data for 2015–2025.
Cite this report
MassOutage (massoutage.com), Mason 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/mason-county