Jefferson County Power Outage History
2014–2025 · Iowa
Average — typical outage frequency and duration nationally. How grades are calculated
Outages by year
Outages by month (seasonality)
Worst outage events on record
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| Jul 16, 2024 | 19 hrs | 5,442 (79%) | Unnamed event |
| Sep 8, 2020 | 2 hrs | 4,656 (67%) | Unnamed event |
| Jul 15, 2020 | 3 hrs | 4,622 (67%) | Unnamed event |
| Jan 23, 2016 | 5 hrs | 4,479 (65%) | Unnamed event |
| Jun 21, 2015 | 9 hrs | 3,906 (57%) | Thunderstorm Wind |
Over the 12 years from 2014 to 2025, Jefferson County recorded 429 distinct power outage events, averaging 1.9 hours per event.
The single worst outage on record in Jefferson County started July 16, 2024, lasting 19 hours and leaving up to 5,442 customers without power (79% of the county) at its peak.
May has historically been the worst month for outages in Jefferson County, with 56 events recorded during that month across the dataset.
Based on this history, Jefferson County earns a Reliability Grade of C, placing it in the 52nd 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 Jefferson County.
| County | Grade | National percentile |
|---|---|---|
| Hardin County | C | 52nd |
| Van Buren County | C | 52nd |
| Worth County | C | 51st |
| Keokuk County | C | 51st |
| Howard County | C | 54th |
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 Jefferson County?
Between 2014 and 2025, Jefferson County recorded 429 outage events, averaging 1.9 hours each.
What is Jefferson County's reliability grade?
Jefferson County has a Reliability Grade of C, in the 52nd national percentile.
What was the worst power outage in Jefferson County?
The worst outage on record started July 16, 2024, lasting 19 hours and affecting up to 5,442 customers.