Dallas 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 | 213 hrs | 19,149 (33%) | Drought |
| Aug 17, 2015 | 3 hrs | 7,066 (12%) | Unnamed event |
| Jul 23, 2022 | 6 hrs | 6,523 (11%) | Unnamed event |
| Sep 23, 2025 | 1 hrs | 6,037 (10%) | Unnamed event |
| Mar 5, 2025 | 21 hrs | 5,911 (10%) | High Wind |
Was There an Outage on a Specific Date?
Pick a date to see whether a power outage was recorded for Dallas County, Iowa that day.
Over the 12 years from 2014 to 2025, Dallas County recorded 273 distinct power outage events, averaging 2.5 hours per event.
The single worst outage on record in Dallas County started August 10, 2020 (Drought), lasting 213 hours and leaving up to 19,149 customers without power (33% of the county) at its peak.
July has historically been the worst month for outages in Dallas County, with 44 events recorded during that month across the dataset.
Based on this history, Dallas County earns a Reliability Grade of B, placing it in the 76th percentile nationally for grid reliability (higher percentile = more reliable).
Similar counties in Iowa
Counties with the closest reliability grade and national percentile to Dallas County.
| County | Grade | National percentile |
|---|---|---|
| Page County | B | 77th |
| Shelby County | B | 77th |
| Floyd County | B | 75th |
| Humboldt County | B | 75th |
| Lyon County | B | 78th |
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 Dallas County?
Between 2014 and 2025, Dallas County recorded 273 outage events, averaging 2.5 hours each.
What is Dallas County's reliability grade?
Dallas County has a Reliability Grade of B, in the 76th national percentile.
What was the worst power outage in Dallas County?
The worst outage on record started August 10, 2020 (Drought), lasting 213 hours and affecting up to 19,149 customers.