Sioux County Power Outage History
2015–2025 · Iowa
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 |
|---|---|---|---|
| Apr 11, 2019 | 29 hrs | 4,636 (27%) | Flood |
| Jul 29, 2025 | 45 hrs | 4,060 (24%) | Excessive Heat |
| Jul 11, 2024 | 1 hrs | 3,265 (19%) | Flood |
| May 11, 2022 | 15 hrs | 3,204 (19%) | Thunderstorm Wind |
| Apr 11, 2019 | 2 hrs | 2,547 (15%) | Flood |
Over the 11 years from 2015 to 2025, Sioux County recorded 189 distinct power outage events, averaging 2.5 hours per event.
The single worst outage on record in Sioux County started April 11, 2019 (Flood), lasting 29 hours and leaving up to 4,636 customers without power (27% of the county) at its peak.
April has historically been the worst month for outages in Sioux County, with 37 events recorded during that month across the dataset.
Based on this history, Sioux County earns a Reliability Grade of A, placing it in the 86th percentile nationally for grid reliability (higher percentile = more reliable).
Sized for Sioux County's outage profile
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Similar counties in Iowa
Counties with the closest reliability grade and national percentile to Sioux County.
| County | Grade | National percentile |
|---|---|---|
| Kossuth County | A | 86th |
| Palo Alto County | A | 86th |
| Buena Vista County | A | 87th |
| Chickasaw County | A | 85th |
| Dickinson County | A | 85th |
FAQ
How often does power go out in Sioux County?
Between 2015 and 2025, Sioux County recorded 189 outage events, averaging 2.5 hours each.
What is Sioux County's reliability grade?
Sioux County has a Reliability Grade of A, in the 86th national percentile.
What was the worst power outage in Sioux County?
The worst outage on record started April 11, 2019 (Flood), lasting 29 hours and affecting up to 4,636 customers.