Shelby 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 19, 2025 | 30 hrs | 2,018 (28%) | Blizzard |
| Oct 20, 2023 | 2 hrs | 1,540 (22%) | Unnamed event |
| Mar 5, 2025 | 14 hrs | 1,065 (15%) | High Wind |
| Apr 26, 2024 | 21 hrs | 1,046 (15%) | Tornado |
| Nov 26, 2015 | 5 hrs | 1,017 (14%) | Winter Storm |
Was There an Outage on a Specific Date?
Pick a date to see whether a power outage was recorded for Shelby County, Iowa that day.
Over the 11 years from 2015 to 2025, Shelby County recorded 262 distinct power outage events, averaging 2.8 hours per event.
The single worst outage on record in Shelby County started March 19, 2025 (Blizzard), lasting 30 hours and leaving up to 2,018 customers without power (28% of the county) at its peak.
July has historically been the worst month for outages in Shelby County, with 42 events recorded during that month across the dataset.
Based on this history, Shelby County earns a Reliability Grade of B, placing it in the 77th percentile nationally for grid reliability (higher percentile = more reliable).
Similar counties in Iowa
Counties with the closest reliability grade and national percentile to Shelby County.
| County | Grade | National percentile |
|---|---|---|
| Page County | B | 77th |
| Lyon County | B | 78th |
| Audubon County | B | 78th |
| Dallas County | B | 76th |
| Crawford County | B | 79th |
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 Shelby County?
Between 2015 and 2025, Shelby County recorded 262 outage events, averaging 2.8 hours each.
What is Shelby County's reliability grade?
Shelby County has a Reliability Grade of B, in the 77th national percentile.
What was the worst power outage in Shelby County?
The worst outage on record started March 19, 2025 (Blizzard), lasting 30 hours and affecting up to 2,018 customers.