County annual report · FIPS 46085
2025 Lyman County, SD Power Outage Report
In 2025, customers in Lyman County, SD went without power for an average of 2.0 hours, a total of 5,818 customer-hours (South Dakota average 6.5 hours). That ranks 40th worst of 65 South Dakota counties and 2427th 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 Lyman 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 | July 23, 2025 13:45 | July 24, 2025 00:15 | 10h 30m | 296 | 1,316 |
| 2 | September 30, 2025 19:30 | September 30, 2025 20:30 | 1h | 227 | 180 |
| 3 | February 19, 2025 13:30 | February 19, 2025 15:00 | 1h 30m | 220 | 160 |
| 4 | June 24, 2025 19:00 | June 24, 2025 20:30 | 1h 30m | 192 | 288 |
| 5 | May 19, 2025 09:15 | May 19, 2025 11:00 | 1h 45m | 181 | 272 |
| 6 | December 9, 2025 01:15 | December 9, 2025 02:15 | 1h | 175 | 160 |
| 7 | July 18, 2025 16:30 | July 18, 2025 17:30 | 1h | 116 | 116 |
| 8 | July 10, 2025 02:30 | July 10, 2025 04:30 | 2h | 111 | 221 |
| 9 | December 18, 2025 12:15 | December 18, 2025 15:30 | 3h 15m | 109 | 246 |
| 10 | December 23, 2025 15:00 | December 23, 2025 19:15 | 4h 15m | 106 | 321 |
Outage episodes by size in 2025: 10 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 Lyman 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 |
|---|---|---|---|---|---|
| West Central Electric Coop Inc - (SD) | 2018 | 3.7 hrs | 1.25 | 1.5 hrs | 1.25 |
| Rosebud Electric Coop Inc | 2024 | 1.9 hrs | 0.84 | 1.6 hrs | 0.76 |
| 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 ÷ 2,969 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. Lyman County has data for 2019–2025.
Cite this report
MassOutage (massoutage.com), Lyman 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/lyman-county