Delaware 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 |
|---|---|---|---|
| Mar 31, 2023 | 20 hrs | 7,198 (78%) | Tornado |
| Dec 26, 2024 | 3 hrs | 3,187 (35%) | Unnamed event |
| Apr 2, 2020 | 1 hrs | 3,052 (33%) | Unnamed event |
| Sep 10, 2019 | 6 hrs | 2,593 (28%) | Thunderstorm Wind |
| Nov 18, 2015 | 2 hrs | 2,270 (25%) | Thunderstorm Wind |
Was There an Outage on a Specific Date?
Pick a date to see whether a power outage was recorded for Delaware County, Iowa that day.
Over the 12 years from 2014 to 2025, Delaware County recorded 278 distinct power outage events, averaging 2.1 hours per event.
The single worst outage on record in Delaware County started March 31, 2023 (Tornado), lasting 20 hours and leaving up to 7,198 customers without power (78% of the county) at its peak.
June has historically been the worst month for outages in Delaware County, with 57 events recorded during that month across the dataset.
Based on this history, Delaware County earns a Reliability Grade of B, placing it in the 72nd percentile nationally for grid reliability (higher percentile = more reliable).
Similar counties in Iowa
Counties with the closest reliability grade and national percentile to Delaware County.
| County | Grade | National percentile |
|---|---|---|
| Winnebago County | B | 72nd |
| Pottawattamie County | B | 72nd |
| Henry County | B | 71st |
| Monona County | B | 74th |
| Taylor County | B | 74th |
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 Delaware County?
Between 2014 and 2025, Delaware County recorded 278 outage events, averaging 2.1 hours each.
What is Delaware County's reliability grade?
Delaware County has a Reliability Grade of B, in the 72nd national percentile.
What was the worst power outage in Delaware County?
The worst outage on record started March 31, 2023 (Tornado), lasting 20 hours and affecting up to 7,198 customers.