County annual report · FIPS 46051
2025 Grant County, SD Power Outage Report
In 2025, customers in Grant County, SD went without power for an average of 5.2 hours, a total of 16K customer-hours (South Dakota average 6.5 hours). That ranks 24th worst of 65 South Dakota counties and 1446th 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 Grant 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 | April 7, 2025 16:30 | April 7, 2025 17:30 | 1h | 1,916 | 1,842 |
| 2 | August 12, 2025 18:00 | August 12, 2025 22:15 | 4h 15m | 1,910 | 5,045 |
| 3 | January 17, 2025 11:15 | January 17, 2025 11:30 | 15m | 1,821 | 455 |
| 4 | July 27, 2025 16:45 | July 27, 2025 19:45 | 3h | 773 | 809 |
| 5 | September 3, 2025 15:45 | September 3, 2025 21:15 | 5h 30m | 609 | 827 |
| 6 | May 15, 2025 22:15 | May 16, 2025 04:30 | 6h 15m | 445 | 1,924 |
| 7 | May 16, 2025 17:15 | May 16, 2025 20:15 | 3h | 310 | 491 |
| 8 | February 28, 2025 18:45 | February 28, 2025 21:45 | 3h | 237 | 228 |
| 9 | June 4, 2025 13:15 | June 5, 2025 19:00 | 1d 5h | 218 | 853 |
| 10 | June 18, 2025 01:15 | June 18, 2025 09:15 | 8h | 144 | 1,119 |
Outage episodes by size in 2025: 11 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 Grant 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 |
|---|---|---|---|---|---|
| Otter Tail Power Co | 2024 | 2.6 hrs | 1.37 | 1.9 hrs | 1.09 |
| Montana-Dakota Utilities Co | 2024 | 2.9 hrs | 1.26 | 2.1 hrs | 1.10 |
| H-D Electric Coop Inc | 2018 | 2.6 hrs | 1.52 | 1.6 hrs | 1.14 |
| Whetstone Valley Elec Coop Inc | 2018 | 73 min | 0.64 | 42 min | 0.43 |
| WAPA-- Western Area Power Administration | - | - | - | - | - |
| Codington-Clark Elec Coop, Inc | - | - | - | - | - |
| City of Big Stone City - (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 ÷ 3,124 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. Grant County has data for 2019–2025.
Cite this report
MassOutage (massoutage.com), Grant 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/grant-county