Lyman 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 |
|---|---|---|---|
| Jul 6, 2023 | <1 hr | 1,281 (22%) | Drought |
| Feb 16, 2021 | 1 hrs | 1,034 (17%) | Extreme Cold/Wind Chill |
| Mar 15, 2021 | 22 hrs | 839 (14%) | Heavy Snow |
| Oct 12, 2020 | 4 hrs | 628 (11%) | Unnamed event |
| Jul 6, 2023 | <1 hr | 592 (10%) | Drought |
Over the 7 years from 2019 to 2025, Lyman County recorded 219 distinct power outage events, averaging 2.9 hours per event.
The single worst outage on record in Lyman County started July 6, 2023 (Drought), lasting less than 1 hour and leaving up to 1,281 customers without power (22% of the county) at its peak.
July has historically been the worst month for outages in Lyman County, with 41 events recorded during that month across the dataset.
Based on this history, Lyman County earns a Reliability Grade of A, placing it in the 81st percentile nationally for grid reliability (higher percentile = more reliable).
Sized for Lyman County's outage profile
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Outage-prep kit
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Similar counties in South Dakota
Counties with the closest reliability grade and national percentile to Lyman County.
| County | Grade | National percentile |
|---|---|---|
| Pennington County | A | 81st |
| Ziebach County | A | 81st |
| Jones County | A | 82nd |
| Brule County | B | 80th |
| Faulk County | B | 79th |
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 Lyman County?
Between 2019 and 2025, Lyman County recorded 219 outage events, averaging 2.9 hours each.
What is Lyman County's reliability grade?
Lyman County has a Reliability Grade of A, in the 81st national percentile.
What was the worst power outage in Lyman County?
The worst outage on record started July 6, 2023 (Drought), lasting less than 1 hour and affecting up to 1,281 customers.