Dewey CountyPower Outage History
What this grade means
Top 20% most reliable nationally — infrequent, short outages. This county ranks in the most reliable fifth of all US counties in our dataset, based on 12 years of real DOE outage records: outages happen less often here, and when they do occur they tend to be resolved quickly compared to the rest of the country. Baseline outage risk is low, though a severe local storm can still occasionally cause a longer-than-usual outage regardless of the long-term track record.
Outages by year
Outages by month (seasonality)
Worst outage events on record
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| Nov 25, 2025 | <1 hr | 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 |
Was There an Outage on a Specific Date?
Pick a date to see whether a power outage was recorded for Dewey County, South Dakota that day.
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 less than 1 hour 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).
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 |
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 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 less than 1 hour and affecting up to 2,114 customers.