Polk CountyPower Outage History
What this grade means
Better than average — fewer or shorter outages than most counties. This county's outage history is better than the national median: recorded outages are less frequent and/or shorter in duration than a typical US county experienced over the same 12-year period. It isn't in the top tier nationally, but its track record points to lower-than-average outage risk.
Outages by year
Outages by month (seasonality)
Worst outage events on record
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| Aug 10, 2020 | 145 hrs | 114,873 (40%) | Drought |
| May 21, 2024 | 26 hrs | 26,999 (9%) | Heavy Rain |
| May 24, 2024 | 28 hrs | 26,759 (9%) | Heavy Rain |
| Jul 28, 2025 | 9 hrs | 24,009 (8%) | Thunderstorm Wind |
| Jul 1, 2018 | 4 hrs | 19,193 (7%) | Flood |
Was There an Outage on a Specific Date?
Pick a date to see whether a power outage was recorded for Polk County, Iowa that day.
Over the 11 years from 2015 to 2025, Polk County recorded 1,354 distinct power outage events, averaging 1.9 hours per event.
The single worst outage on record in Polk County started August 10, 2020 (Drought), lasting 145 hours and leaving up to 114,873 customers without power (40% of the county) at its peak.
June has historically been the worst month for outages in Polk County, with 168 events recorded during that month across the dataset.
Based on this history, Polk County earns a Reliability Grade of B, placing it in the 60th percentile nationally for grid reliability (higher percentile = more reliable).
Similar counties in Iowa
Counties with the closest reliability grade and national percentile to Polk County.
| County | Grade | National percentile |
|---|---|---|
| Fayette County | B | 61st |
| Franklin County | B | 61st |
| Lee County | B | 61st |
| Harrison County | B | 61st |
| Guthrie County | C | 59th |
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 Polk County?
Between 2015 and 2025, Polk County recorded 1,354 outage events, averaging 1.9 hours each.
What is Polk County's reliability grade?
Polk County has a Reliability Grade of B, in the 60th national percentile.
What was the worst power outage in Polk County?
The worst outage on record started August 10, 2020 (Drought), lasting 145 hours and affecting up to 114,873 customers.