Dewey County Power Outage History
2024–2025 · South Dakota
Top 20% most reliable nationally — infrequent, short outages. How grades are calculated
Outages by year
Outages by month (seasonality)
Worst outage events on record
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| Nov 25, 2025 | 1 hrs | 2,114 (22%) | High Wind |
| Nov 14, 2025 | 2 hrs | 2,093 (21%) | Unnamed event |
| Sep 3, 2025 | 6 hrs | 2,090 (21%) | Unnamed event |
| Oct 29, 2025 | 3 hrs | 1,955 (20%) | Unnamed event |
| Jul 14, 2025 | 1 hrs | 1,945 (20%) | Thunderstorm Wind |
Over the 2 years from 2024 to 2025, Dewey County recorded 53 distinct power outage events, averaging 2.6 hours per event.
The single worst outage on record in Dewey County started November 25, 2025 (High Wind), lasting 1 hours and leaving up to 2,114 customers without power (22% of the county) at its peak.
July has historically been the worst month for outages in Dewey County, with 10 events recorded during that month across the dataset.
Based on this history, Dewey County earns a Reliability Grade of A, placing it in the 96th percentile nationally for grid reliability (higher percentile = more reliable).
Sized for Dewey County's outage profile
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Similar counties in South Dakota
Counties with the closest reliability grade and national percentile to Dewey County.
| County | Grade | National percentile |
|---|---|---|
| Hand County | A | 96th |
| Oglala Lakota County | A | 96th |
| Corson County | A | 96th |
| Jerauld County | A | 96th |
| Potter County | A | 94th |
FAQ
How often does power go out in Dewey County?
Between 2024 and 2025, Dewey County recorded 53 outage events, averaging 2.6 hours each.
What is Dewey County's reliability grade?
Dewey County has a Reliability Grade of A, in the 96th national percentile.
What was the worst power outage in Dewey County?
The worst outage on record started November 25, 2025 (High Wind), lasting 1 hours and affecting up to 2,114 customers.