County annual report · FIPS 46031
2025 Corson County, SD Power Outage Report
In 2025, customers in Corson County, SD went without power for an average of 2.3 hours, a total of 4,570 customer-hours (South Dakota average 6.5 hours). That ranks 33rd worst of 65 South Dakota counties and 2308th 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 Corson 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 21, 2025 18:15 | August 21, 2025 19:45 | 1h 30m | 201 | 126 |
| 2 | July 27, 2025 08:15 | July 27, 2025 13:30 | 5h 15m | 141 | 476 |
| 3 | March 5, 2025 19:15 | March 5, 2025 22:45 | 3h 30m | 138 | 419 |
| 4 | June 9, 2025 21:45 | June 9, 2025 22:00 | 15m | 119 | 30 |
| 5 | June 21, 2025 03:00 | June 21, 2025 10:45 | 7h 45m | 111 | 658 |
| 6 | August 4, 2025 14:15 | August 4, 2025 15:30 | 1h 15m | 108 | 109 |
| 7 | April 25, 2025 13:15 | April 25, 2025 15:00 | 1h 45m | 77 | 41 |
| 8 | October 13, 2025 22:30 | October 13, 2025 23:30 | 1h | 75 | 72 |
| 9 | May 3, 2025 07:00 | May 3, 2025 08:45 | 1h 45m | 74 | 111 |
| 10 | May 19, 2025 13:30 | May 19, 2025 15:00 | 1h 30m | 69 | 104 |
Outage episodes by size in 2025: 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 Corson 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 |
| Grand Electric Coop, Inc | - | - | - | - | - |
| Moreau-Grand Electric Coop Inc | - | - | - | - | - |
| City of McLaughlin - (SD) | - | - | - | - | - |
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 ÷ 1,975 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. Corson County has data for 2017–2025.
Cite this report
MassOutage (massoutage.com), Corson 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/corson-county