Grundy CountyPower Outage History
What this grade means
(How grades are calculated)Average — typical outage frequency and duration nationally. This county sits in the middle of the national distribution — its outage frequency and duration over the past 12 years are close to the nationwide median, neither notably better nor worse than most other US counties. A typical amount of backup-power preparedness is reasonable here.
Outages by year
Outages by month (seasonality)
Worst outage events on record
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| Aug 10, 2020 | 5 hrs | 2,341 (38%) | Thunderstorm Wind |
| Aug 10, 2020 | 207 hrs | 2,341 (38%) | Thunderstorm Wind |
| Mar 29, 2021 | 15 hrs | 1,846 (30%) | Unnamed event |
| Apr 1, 2023 | 3 hrs | 1,671 (27%) | Tornado |
| Feb 13, 2015 | <1 hr | 1,543 (25%) | Unnamed event |
Was There an Outage on a Specific Date?
Pick a date to see whether a power outage was recorded for Grundy County, Iowa that day.
Over the 12 years from 2014 to 2025, Grundy County recorded 286 distinct power outage events, averaging 4.2 hours per event.
The single worst outage on record in Grundy County started August 10, 2020 (Thunderstorm Wind), lasting 5 hours and leaving up to 2,341 customers without power (38% of the county) at its peak.
May has historically been the worst month for outages in Grundy County, with 39 events recorded during that month across the dataset.
Based on this history, Grundy County earns a Reliability Grade of C, placing it in the 46th percentile nationally for grid reliability (higher percentile = more reliable).
Similar counties in Iowa
Counties with the closest reliability grade and national percentile to Grundy County.
| County | Grade | National percentile |
|---|---|---|
| Jones County | C | 45th |
| Calhoun County | C | 47th |
| Washington County | C | 47th |
| Louisa County | C | 44th |
| Appanoose County | C | 48th |
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 Grundy County?
Between 2014 and 2025, Grundy County recorded 286 outage events, averaging 4.2 hours each.
What is Grundy County's reliability grade?
Grundy County has a Reliability Grade of C, in the 46th national percentile.
What was the worst power outage in Grundy County?
The worst outage on record started August 10, 2020 (Thunderstorm Wind), lasting 5 hours and affecting up to 2,341 customers.