County annual report · FIPS 56033
2025 Sheridan County, WY Power Outage Report
In 2025, customers in Sheridan County, WY went without power for an average of 4.5 hours, a total of 80K customer-hours (Wyoming average 3.8 hours). That ranks 9th worst of 20 Wyoming counties and 1627th of 3,000 nationally.
Compared with WY, the US and 2024
Coverage line is EAGLE-I's share of Wyoming customers tracked each year.
Biggest outages in Sheridan 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 | November 13, 2025 16:15 | November 18, 2025 21:30 | 5d 5h | 12,017 | 49K |
| 2 | May 31, 2025 23:45 | June 1, 2025 05:00 | 5h 15m | 1,653 | 4,459 |
| 3 | December 17, 2025 21:30 | January 1, 2026 00:00 | 14d 2h | 1,045 | 14K |
| 4 | September 1, 2025 03:30 | September 1, 2025 16:45 | 13h 15m | 960 | 396 |
| 5 | April 9, 2025 16:00 | April 9, 2025 17:00 | 1h | 588 | 454 |
| 6 | July 18, 2025 17:45 | July 18, 2025 19:30 | 1h 45m | 448 | 353 |
| 7 | August 21, 2025 23:00 | August 22, 2025 00:30 | 1h 30m | 396 | 311 |
| 8 | August 2, 2025 03:30 | August 2, 2025 04:00 | 30m | 386 | 97 |
| 9 | May 20, 2025 20:15 | May 20, 2025 20:45 | 30m | 378 | 189 |
| 10 | May 20, 2025 14:15 | May 20, 2025 14:30 | 15m | 364 | 91 |
Outage episodes by size in 2025: 18 reached 100+ customers, 3 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 Sheridan 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 |
|---|---|---|---|---|---|
| Montana-Dakota Utilities Co | 2024 | 2.9 hrs | 1.26 | 2.1 hrs | 1.10 |
| Powder River Energy Corp | 2024 | 8.3 hrs | 2.88 | 4.9 hrs | 2.24 |
| Big Horn Rural Electric Co | 2018 | 4.0 hrs | 1.80 | - | - |
| Big Horn County Elec Coop, Inc | - | - | - | - | - |
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 Wyoming's customers in 2025; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 17,618 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. Sheridan County has data for 2017–2025.
Cite this report
MassOutage (massoutage.com), Sheridan County, WY 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/wyoming/sheridan-county