Clarke CountyPower Outage History
What this grade means
(How grades are calculated)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 |
|---|---|---|---|
| Jun 28, 2018 | 5 hrs | 1,254 (29%) | Thunderstorm Wind |
| Oct 25, 2024 | 3 hrs | 1,248 (29%) | Hail |
| May 17, 2015 | 12 hrs | 1,131 (26%) | Thunderstorm Wind |
| Feb 2, 2016 | <1 hr | 1,065 (25%) | Unnamed event |
| Jan 11, 2021 | <1 hr | 907 (21%) | Unnamed event |
Was There an Outage on a Specific Date?
Pick a date to see whether a power outage was recorded for Clarke County, Iowa that day.
Over the 11 years from 2015 to 2025, Clarke County recorded 330 distinct power outage events, averaging 2.0 hours per event.
The single worst outage on record in Clarke County started June 28, 2018 (Thunderstorm Wind), lasting 5 hours and leaving up to 1,254 customers without power (29% of the county) at its peak.
August has historically been the worst month for outages in Clarke County, with 55 events recorded during that month across the dataset.
Based on this history, Clarke County earns a Reliability Grade of A, placing it in the 80th percentile nationally for grid reliability (higher percentile = more reliable).
Similar counties in Iowa
Counties with the closest reliability grade and national percentile to Clarke County.
| County | Grade | National percentile |
|---|---|---|
| Cerro Gordo County | A | 80th |
| Clayton County | A | 80th |
| Hamilton County | B | 80th |
| Decatur County | B | 79th |
| Madison County | A | 81st |
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 Clarke County?
Between 2015 and 2025, Clarke County recorded 330 outage events, averaging 2.0 hours each.
What is Clarke County's reliability grade?
Clarke County has a Reliability Grade of A, in the 80th national percentile.
What was the worst power outage in Clarke County?
The worst outage on record started June 28, 2018 (Thunderstorm Wind), lasting 5 hours and affecting up to 1,254 customers.