County annual report · FIPS 46033
2025 Custer County, SD Power Outage Report
In 2025, customers in Custer County, SD went without power for an average of 66.0 hours, a total of 296K customer-hours (South Dakota average 6.5 hours). That ranks 1st worst of 65 South Dakota counties and 51st of 3,000 nationally.
Compared with SD, the US and 2024
Coverage line is EAGLE-I's share of South Dakota customers tracked each year.
Biggest outages in Custer 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 | December 18, 2025 08:00 | January 1, 2026 00:00 | 13d 16h | 5,295 | 262K |
| 2 | November 13, 2025 19:45 | November 14, 2025 05:45 | 10h | 4,910 | 15K |
| 3 | July 6, 2025 10:30 | July 6, 2025 16:00 | 5h 30m | 1,120 | 3,968 |
| 4 | August 22, 2025 11:45 | August 22, 2025 16:15 | 4h 30m | 744 | 1,495 |
| 5 | August 5, 2025 20:45 | August 6, 2025 04:00 | 7h 15m | 737 | 1,717 |
| 6 | August 6, 2025 21:15 | August 6, 2025 21:45 | 30m | 735 | 368 |
| 7 | October 13, 2025 20:30 | October 13, 2025 21:00 | 30m | 545 | 273 |
| 8 | January 4, 2025 19:00 | January 6, 2025 17:15 | 1d 22h | 501 | 2,223 |
| 9 | December 1, 2025 18:45 | December 2, 2025 19:00 | 1d | 476 | 143 |
| 10 | April 27, 2025 12:30 | April 28, 2025 09:45 | 21h 15m | 292 | 2,412 |
Outage episodes by size in 2025: 17 reached 100+ customers, 3 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 Custer 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 |
|---|---|---|---|---|---|
| Black Hills Power, Inc. | 2024 | 40 min | 0.70 | 40 min | 0.70 |
| Black Hills Electric Coop, Inc | 2024 | 3.8 hrs | 1.03 | 1.7 hrs | 0.77 |
| WAPA-- Western Area Power Administration | - | - | - | - | - |
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 South Dakota's customers in 2025; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 4,481 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. Custer County has data for 2016–2025.
Cite this report
MassOutage (massoutage.com), Custer County, SD 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/south-dakota/custer-county