Stanley CountyPower Outage History
2019–2025 · South Dakota
Top 20% most reliable nationally — infrequent, short outages.
Outages by year
Outages by month (seasonality)
Worst outage events on record
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| Jun 29, 2025 | 9 hrs | 516 (13%) | Unnamed event |
| Apr 15, 2025 | 3 hrs | 515 (13%) | Drought |
| Apr 18, 2023 | <1 hr | 502 (13%) | Unnamed event |
| Aug 17, 2021 | <1 hr | 484 (12%) | Drought |
| Feb 2, 2021 | <1 hr | 478 (12%) | Unnamed event |
Over the 7 years from 2019 to 2025, Stanley County recorded 149 distinct power outage events, averaging 2.8 hours per event.
The single worst outage on record in Stanley County started June 29, 2025, lasting 9 hours and leaving up to 516 customers without power (13% of the county) at its peak.
June has historically been the worst month for outages in Stanley County, with 30 events recorded during that month across the dataset.
Based on this history, Stanley County earns a Reliability Grade of A, placing it in the 93rd percentile nationally for grid reliability (higher percentile = more reliable).
Sized for Stanley County's outage profile
See more picks in our Best Small Power Stations (Under 1,000Wh) roundup.
Outage-prep kit
See our outage-prep guides.
Similar counties in South Dakota
Counties with the closest reliability grade and national percentile to Stanley County.
| County | Grade | National percentile |
|---|---|---|
| Edmunds County | A | 93rd |
| Lincoln County | A | 92nd |
| Mellette County | A | 92nd |
| Campbell County | A | 93rd |
| Walworth County | A | 94th |
Most reliable counties in South Dakota
The top 3 counties in South Dakota by reliability grade and percentile.
| County | Grade | National percentile |
|---|---|---|
| Clay County | A | 100th |
| Codington County | A | 98th |
| Tripp County | A | 98th |
Least reliable counties in South Dakota
The bottom 3 counties in South Dakota by reliability grade and percentile.
| County | Grade | National percentile |
|---|---|---|
| Harding County | D | 21st |
| Perkins County | D | 29th |
| Custer County | D | 30th |
Most reliable counties nationally
The top 3 counties nationally by reliability grade and percentile.
| County | State | Grade | National percentile |
|---|---|---|---|
| Clay County | South Dakota | A | 100th |
| Clearwater County | Minnesota | A | 99th |
| Limestone County | Alabama | A | 99th |
Least reliable counties nationally
The bottom 3 counties nationally by reliability grade and percentile.
| County | State | Grade | National percentile |
|---|---|---|---|
| Clay County | West Virginia | F | 0th |
| Lincoln County | West Virginia | F | 0th |
| Cameron Parish | Louisiana | F | 0th |
FAQ
How often does power go out in Stanley County?
Between 2019 and 2025, Stanley County recorded 149 outage events, averaging 2.8 hours each.
What is Stanley County's reliability grade?
Stanley County has a Reliability Grade of A, in the 93rd national percentile.
What was the worst power outage in Stanley County?
The worst outage on record started June 29, 2025, lasting 9 hours and affecting up to 516 customers.