County annual report · FIPS 46041
2025 Dewey County, SD Power Outage Report
In 2025, customers in Dewey County, SD went without power for an average of 6.7 hours, a total of 33K customer-hours (South Dakota average 6.5 hours). That ranks 17th worst of 65 South Dakota counties and 1197th 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 Dewey 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 25, 2025 14:30 | November 25, 2025 18:00 | 3h 30m | 2,114 | 608 |
| 2 | November 14, 2025 15:15 | November 14, 2025 16:45 | 1h 30m | 2,093 | 3,140 |
| 3 | September 3, 2025 12:15 | September 3, 2025 18:15 | 6h | 2,090 | 7,098 |
| 4 | October 29, 2025 12:15 | October 29, 2025 15:00 | 2h 45m | 1,955 | 4,182 |
| 5 | July 14, 2025 23:30 | July 15, 2025 00:45 | 1h 15m | 1,945 | 761 |
| 6 | July 10, 2025 01:00 | July 11, 2025 16:00 | 1d 15h | 567 | 5,890 |
| 7 | March 15, 2025 01:00 | March 15, 2025 08:00 | 7h | 398 | 1,278 |
| 8 | October 27, 2025 16:45 | October 27, 2025 22:45 | 6h | 288 | 1,728 |
| 9 | December 18, 2025 13:30 | December 18, 2025 17:15 | 3h 45m | 246 | 274 |
| 10 | December 11, 2025 21:45 | December 12, 2025 00:15 | 2h 30m | 244 | 549 |
Outage episodes by size in 2025: 19 reached 100+ customers, 5 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 Dewey 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 |
|---|---|---|---|---|---|
| WAPA-- Western Area Power Administration | - | - | - | - | - |
| Moreau-Grand Electric 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 South Dakota's customers in 2025; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 4,866 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. Dewey County has data for 2024–2025.
Cite this report
MassOutage (massoutage.com), Dewey 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/). https://massoutage.com/reports/2025/south-dakota/dewey-county