Power outage history
Cerro Gordo County Iowa
2.3hours
without power for the average customer in a typical year, 2018–2025
70th most of 98 in Iowa 65% below the national median
Every day since 2015
Eleven years, one night at a time
Each cell is a day. The brighter it is, the larger the share of Cerro Gordo's customers who were without power at that day's worst moment.
Year by year
Hours in the dark, per customer
2021 was the worst well-recorded year, at 5.6 hours for the average customer. Hatched years have a thin record and are left out of the averages.
Cerro Gordo, hours without power per customer
The record
The biggest outages since 2015
Ranked by customer-hours lost: customers out multiplied by how long they stayed out. Times are local.
| Began | Storm | Peak out | Share | Lasted | 90% restored | Customer-hours |
|---|---|---|---|---|---|---|
| Dec 15, 2021 | Tornadoes | 13,943 | 47% | 29 h | 17 h | 123k |
| May 28, 2018 | Thunderstorms | 10,632 | 36% | 21 h | 6.8 h | 53k |
| Jul 29, 2025 | Thunderstorms | 7,467 | 25% | 14 h | 12 h | 32k |
| Jul 19, 2017 | Thunderstorms | 16,188 | 55% | 5.0 h | 1.2 h | 24k |
| Mar 24, 2018 | Winter storm | 4,394 | 15% | 15 h | 9.5 h | 23k |
| Aug 27, 2021 | Thunderstorms | 7,327 | 25% | 1.8 h | 48 min | 10k |
| Jul 27, 2025 | Thunderstorms | 1,033 | 4% | 16 h | – | 9.9k |
| Aug 16, 2023 | No storm report | 7,186 | 24% | 1.8 h | 1.0 h | 9.7k |
| Aug 27, 2018 | No storm report | 663 | 2% | 15 h | – | 9.6k |
| May 17, 2017 | No storm report | 593 | 2% | 16 h | – | 9.0k |
| Apr 12, 2022 | Thunderstorms | 3,211 | 11% | 6.2 h | 3.5 h | 7.8k |
| Aug 9, 2025 | No storm report | 1,182 | 4% | 7.0 h | – | 5.8k |
| Apr 10, 2017 | Thunderstorms | 1,322 | 4% | 3.2 h | – | 4.3k |
| Nov 27, 2019 | Winter storm | 1,149 | 4% | 5.5 h | – | 4.1k |
| Jun 2, 2018 | Thunderstorms | 2,554 | 9% | 4.2 h | 4.2 h | 3.6k |
| Aug 28, 2021 | Thunderstorms | 1,801 | 6% | 2.0 h | 2.0 h | 3.6k |
| May 21, 2024 | Thunderstorms | 1,751 | 6% | 2.2 h | 1.2 h | 3.5k |
| Jul 20, 2019 | Thunderstorms | 1,754 | 6% | 3.0 h | 2.2 h | 3.1k |
| Nov 12, 2015 | Windstorm | 1,940 | 7% | 2.5 h | 1.8 h | 2.9k |
| Mar 20, 2019 | Flooding | 1,445 | 5% | 2.0 h | – | 2.9k |
| Jul 9, 2020 | Thunderstorms | 1,934 | 7% | 1.5 h | 1.0 h | 2.9k |
| Dec 10, 2021 | Winter storm | 1,012 | 3% | 3.0 h | – | 2.7k |
| Sep 22, 2016 | Thunderstorms | 913 | 3% | 4.5 h | – | 2.7k |
| Sep 26, 2021 | No storm report | 1,741 | 6% | 1.5 h | 1.0 h | 2.6k |
| Sep 28, 2016 | No storm report | 2,609 | 9% | 1.0 h | 48 min | 2.4k |
| Jun 9, 2017 | No storm report | 1,769 | 6% | 1.5 h | 1.5 h | 2.4k |
| Jun 20, 2025 | Thunderstorms | 1,196 | 4% | 2.0 h | – | 2.4k |
| Apr 13, 2018 | No storm report | 2,351 | 8% | 1.0 h | 1.0 h | 2.4k |
| May 21, 2024 | Thunderstorms | 884 | 3% | 2.8 h | – | 2.3k |
| Apr 2, 2022 | No storm report | 1,815 | 6% | 1.2 h | 1.2 h | 2.3k |
After the peak
How fast the lights come back
Each line is one major outage, from its peak. The amber line is the typical path.
When it happens
The outage clock
Customer-hours out by month (rings, January innermost) and local hour, 2018–2025.
What was happening
Weather behind the outages
Each outage is matched to NOAA storm reports for Cerro Gordo from twelve hours before it began to its peak. Matching shows coincidence, not proof of cause.
- Thunderstorms 37%
- Tornadoes 32%
- No storm on record 22%
- Winter storm 8.3%
- Flooding 0.8%
Who keeps the lights on
Utilities serving Cerro Gordo
As each utility reports to the Energy Information Administration for its whole Iowa territory, not this county alone. Outage minutes include major storm days.
| Utility | Type | Outage min / yr | Excl. major storms | Outages / yr | Residential ¢/kWh | Customers |
|---|---|---|---|---|---|---|
| MidAmerican Energy Co | Investor Owned | 205 | 82 | 1.19 | 11.2 | 640k |
| Interstate Power and Light Co | Investor Owned | 89 | 74 | 0.82 | 17.8 | 419k |
| Franklin Rural Electric Coop | IA | 178 | 178 | 1.48 | 12.7 | 31k |
| Heartland Power Coop | Cooperative | 117 | 67 | 0.92 | 12.8 | 4.4k |
| Butler County Rural Elec Coop | Cooperative | 97 | 85 | 1.45 | 14.5 | 3.9k |
| Prairie Energy Coop | Cooperative | 428 | 121 | 3.11 | 14.1 | 3.4k |
EIA Form 861, latest year each utility reported. Outage minutes are SAIDI, the yearly minutes the average customer goes without power; outages a year are SAIFI.
About these numbers
Notes
Outages come from the EAGLE-I record of utility outage maps collected every 15 minutes by Oak Ridge National Laboratory. Hours without power are customer-hours divided by the county's 29,435 electricity customers. Averages use well-covered years from 2018. Outages shorter than 15 minutes, and utilities that publish no outage map, are not in the record, so these figures understate the total. How every number is made →