Clayton County Power Outage History
2014–2025 · 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 |
|---|---|---|---|
| Jul 19, 2017 | 27 hrs | 4,994 (47%) | Thunderstorm Wind |
| Jun 22, 2015 | 12 hrs | 3,186 (30%) | Hail |
| Jan 18, 2020 | 1 hrs | 2,876 (27%) | Winter Storm |
| Jan 25, 2019 | 2 hrs | 2,712 (25%) | Heavy Snow |
| Mar 6, 2018 | 2 hrs | 1,941 (18%) | Unnamed event |
Over the 12 years from 2014 to 2025, Clayton County recorded 253 distinct power outage events, averaging 2.5 hours per event.
The single worst outage on record in Clayton County started July 19, 2017 (Thunderstorm Wind), lasting 27 hours and leaving up to 4,994 customers without power (47% of the county) at its peak.
July has historically been the worst month for outages in Clayton County, with 47 events recorded during that month across the dataset.
Based on this history, Clayton County earns a Reliability Grade of A, placing it in the 80th percentile nationally for grid reliability (higher percentile = more reliable).
Sized for Clayton County's outage profile
See more picks in our Best Small Power Stations (Under 1,000Wh) roundup.
Outage-prep kit
See our outage-prep guides.
Similar counties in Iowa
Counties with the closest reliability grade and national percentile to Clayton County.
| County | Grade | National percentile |
|---|---|---|
| Clarke County | A | 80th |
| Cerro Gordo County | A | 80th |
| Hamilton County | B | 80th |
| Madison County | A | 81st |
| Decatur County | B | 79th |
FAQ
How often does power go out in Clayton County?
Between 2014 and 2025, Clayton County recorded 253 outage events, averaging 2.5 hours each.
What is Clayton County's reliability grade?
Clayton County has a Reliability Grade of A, in the 80th national percentile.
What was the worst power outage in Clayton County?
The worst outage on record started July 19, 2017 (Thunderstorm Wind), lasting 27 hours and affecting up to 4,994 customers.