Walworth CountyPower Outage History
2017–2025 · 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 |
|---|---|---|---|
| Oct 14, 2021 | 4 hrs | 2,454 (45%) | Drought |
| Jun 4, 2017 | 3 hrs | 2,073 (38%) | Unnamed event |
| Sep 28, 2022 | <1 hr | 2,021 (37%) | Unnamed event |
| Oct 18, 2017 | <1 hr | 1,777 (33%) | Drought |
| Nov 14, 2017 | <1 hr | 1,717 (32%) | Unnamed event |
Over the 9 years from 2017 to 2025, Walworth County recorded 150 distinct power outage events, averaging 1.3 hours per event.
The single worst outage on record in Walworth County started October 14, 2021 (Drought), lasting 4 hours and leaving up to 2,454 customers without power (45% of the county) at its peak.
July has historically been the worst month for outages in Walworth County, with 35 events recorded during that month across the dataset.
Based on this history, Walworth County earns a Reliability Grade of A, placing it in the 94th percentile nationally for grid reliability (higher percentile = more reliable).
Sized for Walworth County's outage profile
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Similar counties in South Dakota
Counties with the closest reliability grade and national percentile to Walworth County.
| County | Grade | National percentile |
|---|---|---|
| Buffalo County | A | 94th |
| Campbell County | A | 93rd |
| Potter County | A | 94th |
| Edmunds County | A | 93rd |
| Stanley County | A | 93rd |
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 Walworth County?
Between 2017 and 2025, Walworth County recorded 150 outage events, averaging 1.3 hours each.
What is Walworth County's reliability grade?
Walworth County has a Reliability Grade of A, in the 94th national percentile.
What was the worst power outage in Walworth County?
The worst outage on record started October 14, 2021 (Drought), lasting 4 hours and affecting up to 2,454 customers.