County annual report · FIPS 46135
2021 Yankton County, SD Power Outage Report
In 2021, customers in Yankton County, SD went without power for an average of 1.4 hours, a total of 17K customer-hours (South Dakota average 3.4 hours). That ranks 46th worst of 61 South Dakota counties and 2498th of 2,974 nationally.
Compared with SD, the US and 2020
Coverage line is EAGLE-I's share of South Dakota customers tracked each year.
Biggest outages in Yankton County, 2021
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | January 10, 2021 17:00 | January 10, 2021 18:15 | 1h 15m | 1,795 | 1,997 |
| 2 | May 9, 2021 03:45 | May 9, 2021 06:00 | 2h 15m | 1,756 | 3,951 |
| 3 | November 12, 2021 16:30 | November 12, 2021 18:30 | 2h | 965 | 1,166 |
| 4 | May 8, 2021 18:15 | May 8, 2021 21:30 | 3h 15m | 621 | 1,273 |
| 5 | December 16, 2021 04:30 | December 16, 2021 11:15 | 6h 45m | 399 | 1,026 |
| 6 | July 8, 2021 15:30 | July 8, 2021 17:45 | 2h 15m | 395 | 889 |
| 7 | July 15, 2021 08:00 | July 15, 2021 11:45 | 3h 45m | 220 | 743 |
| 8 | September 17, 2021 05:30 | September 17, 2021 10:30 | 5h | 82 | 326 |
| 9 | April 5, 2021 15:30 | April 5, 2021 22:45 | 7h 15m | 52 | 233 |
| 10 | November 17, 2021 15:00 | November 17, 2021 19:45 | 4h 45m | 52 | 206 |
Outage episodes by size in 2021: 7 reached 100+ customers, 2 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 Yankton County reported on EIA Form 861 for 2021, 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 |
|---|---|---|---|---|---|
| NorthWestern Energy - (SD) | 2021 | 1.5 hrs | 0.95 | 81 min | 0.83 |
| Bon Homme Yankton El Assn, Inc | 2018 | 34 min | 0.32 | 34 min | 0.32 |
| WAPA-- Western Area Power Administration | - | - | - | - | - |
| Southeastern Electric Coop Inc - (SD) | - | - | - | - | - |
| Clay-Union Electric Corp | - | - | - | - | - |
About this data
- Outage figures come from DOE/ORNL EAGLE-I, which records customers out by county every 15 minutes. EAGLE-I tracked about 79% of South Dakota's customers in 2021; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 11,940 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. Yankton County has data for 2019–2025.
Cite this report
MassOutage (massoutage.com), Yankton County, SD annual power outage report, 2021, 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/2021/south-dakota/yankton-county