County annual report · FIPS 17111
2025 McHenry County, IL Power Outage Report
In 2025, customers in McHenry County, IL went without power for an average of 3.0 hours, a total of 364K customer-hours (Illinois average 2.5 hours). That ranks 57th worst of 102 Illinois counties and 2054th of 3,000 nationally.
Compared with IL, the US and 2024
Coverage line is EAGLE-I's share of Illinois customers tracked each year.
Biggest outages in McHenry County, 2025
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | August 16, 2025 17:30 | August 19, 2025 23:15 | 3d 5h | 13,250 | 231K |
| 2 | March 15, 2025 04:15 | March 16, 2025 16:45 | 1d 12h | 4,280 | 27K |
| 3 | July 12, 2025 22:00 | July 13, 2025 06:15 | 8h 15m | 3,302 | 2,289 |
| 4 | May 15, 2025 23:30 | May 17, 2025 22:00 | 1d 22h | 3,116 | 14K |
| 5 | November 26, 2025 06:30 | November 27, 2025 01:30 | 19h | 2,273 | 4,075 |
| 6 | June 21, 2025 08:00 | June 22, 2025 10:15 | 1d 2h | 1,554 | 3,886 |
| 7 | July 10, 2025 20:30 | July 12, 2025 04:30 | 1d 8h | 1,321 | 7,979 |
| 8 | January 13, 2025 07:15 | January 13, 2025 13:00 | 5h 45m | 1,237 | 1,195 |
| 9 | March 19, 2025 22:15 | March 20, 2025 19:00 | 20h 45m | 1,184 | 645 |
| 10 | March 29, 2025 04:00 | March 29, 2025 11:00 | 7h | 993 | 1,385 |
Outage episodes by size in 2025: 103 reached 100+ customers, 9 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 McHenry County reported on EIA Form 861 for 2025, 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 | 2024 | 2.2 hrs | 0.68 | 36 min | 0.49 |
| Rock Energy Cooperative | 2024 | 53 min | 0.48 | 27 min | 0.36 |
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 2025; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 120,381 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. McHenry County has data for 2015–2025.
Cite this report
MassOutage (massoutage.com), McHenry County, IL annual power outage report, 2025, 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/2025/illinois/mchenry-county