Power outage history
Sac County Iowa
5.2hours
without power for the average customer in a typical year, 2018–2025
32nd most of 98 in Iowa 22% 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 Sac's customers who were without power at that day's worst moment.
Year by year
Hours in the dark, per customer
2025 was the worst well-recorded year, at 18 hours for the average customer. Hatched years have a thin record and are left out of the averages.
Sac, 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 |
|---|---|---|---|---|---|---|
| Mar 19, 2025 | Winter storm | 3,463 | 89% | 27 h | 20 h | 39k |
| Dec 10, 2021 | No storm report | 2,274 | 58% | 12 h | 4.2 h | 14k |
| Mar 4, 2025 | Winter storm | 761 | 20% | 24 h | 15 h | 11k |
| Jun 16, 2021 | Thunderstorms | 1,210 | 31% | 16 h | 11 h | 7.2k |
| Apr 18, 2025 | No storm report | 498 | 13% | 13 h | 5.0 h | 6.3k |
| Jun 7, 2024 | No storm report | 757 | 19% | 12 h | 8.8 h | 6.0k |
| Jun 16, 2024 | Thunderstorms | 754 | 19% | 10 h | 7.5 h | 5.9k |
| May 19, 2025 | No storm report | 1,296 | 33% | 4.0 h | 3.2 h | 5.0k |
| May 16, 2017 | Thunderstorms | 573 | 15% | 15 h | 14 h | 4.2k |
| Sep 28, 2021 | No storm report | 760 | 20% | 5.2 h | 3.8 h | 4.0k |
| Dec 15, 2021 | Tornadoes | 1,818 | 47% | 5.8 h | 4.5 h | 3.9k |
| Nov 26, 2015 | No storm report | 544 | 14% | 16 h | 9.0 h | 3.0k |
| Oct 2, 2024 | No storm report | 1,210 | 31% | 2.8 h | 2.0 h | 2.7k |
| Jul 23, 2022 | Thunderstorms | 1,217 | 31% | 2.2 h | 1.0 h | 2.5k |
| Mar 6, 2016 | No storm report | 1,234 | 32% | 2.0 h | 1.8 h | 2.5k |
| Jan 30, 2025 | No storm report | 520 | 13% | 4.8 h | 3.5 h | 2.2k |
| Jul 30, 2024 | Thunderstorms | 789 | 20% | 4.5 h | 30 min | 2.1k |
| Mar 16, 2018 | No storm report | 1,360 | 35% | 1.8 h | 1.0 h | 2.0k |
| May 7, 2024 | No storm report | 1,282 | 33% | 1.5 h | 3.0 h | 1.9k |
| Apr 14, 2018 | Winter storm | 234 | 6% | 23 h | 10 h | 1.8k |
| Nov 11, 2020 | No storm report | 392 | 10% | 4.5 h | 4.8 h | 1.8k |
| Aug 10, 2020 | Thunderstorms | 907 | 23% | 5.8 h | 1.5 h | 1.7k |
| May 30, 2022 | No storm report | 516 | 13% | 3.0 h | 48 min | 1.5k |
| Jun 10, 2020 | No storm report | 515 | 13% | 4.8 h | 4.2 h | 1.5k |
| Mar 14, 2025 | Thunderstorms | 796 | 20% | 4.0 h | 1.0 h | 1.5k |
| Jul 15, 2024 | Thunderstorms | 755 | 19% | 2.2 h | 1.8 h | 1.4k |
| Nov 10, 2020 | No storm report | 459 | 12% | 6.0 h | 3.5 h | 1.4k |
| Dec 9, 2019 | No storm report | 757 | 19% | 6.2 h | 1.2 h | 1.3k |
| May 30, 2022 | No storm report | 960 | 25% | 2.2 h | 2.2 h | 1.3k |
| Jun 1, 2021 | No storm report | 1,573 | 40% | 2.0 h | 30 min | 964 |
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 Sac from twelve hours before it began to its peak. Matching shows coincidence, not proof of cause.
- No storm on record 47%
- Winter storm 35%
- Thunderstorms 15%
- Tornadoes 3.1%
Who keeps the lights on
Utilities serving Sac
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 |
| Western Iowa Power Coop | IA | 27 | 27 | 0.27 | 13.5 | 69k |
| Raccoon Valley Electric Cooperative | IA | 39 | 39 | 0.56 | 14.0 | 49k |
| Calhoun County Elec Coop Assn | IA | 21 | 21 | 0.20 | 14.2 | 32k |
| City of Lake View | IA | – | – | – | – | 13k |
| Iowa Lakes Electric Coop | Cooperative | 55 | 54 | 0.44 | 13.8 | 9.8k |
| North West Rural Electric Coop | Cooperative | 188 | 115 | 1.11 | 9.4 | 9.5k |
| City of Wall Lake | IA | – | – | – | – | 4.8k |
| City of Auburn | IA | – | – | – | – | 1.5k |
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.
Next door
Neighbouring counties
- Calhoun 6.8 h
- Sac (this county) 5.2 h
- Ida 3.6 h
- Pocahontas 2.8 h
- Cherokee 2.1 h
- Crawford 2.1 h
- Buena Vista 2.0 h
- Carroll 1.6 h
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 3,895 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 →