Grundy CountyPower Outage History
2014–2025 · Iowa
Average — typical outage frequency and duration nationally.
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 |
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).
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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 in Iowa
The top 3 counties in Iowa by reliability grade and percentile.
| County | Grade | National percentile |
|---|---|---|
| Clay County | A | 97th |
| Emmet County | A | 95th |
| Bremer County | A | 94th |
Least reliable counties in Iowa
The bottom 3 counties in Iowa by reliability grade and percentile.
| County | Grade | National percentile |
|---|---|---|
| Marshall County | F | 6th |
| Tama County | F | 12th |
| Jasper County | F | 14th |
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.