Power outage history
Cass County Iowa
1.3hours
without power for the average customer in a typical year, 2018–2025
95th most of 98 in Iowa 80% 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 Cass's customers who were without power at that day's worst moment.
Year by year
Hours in the dark, per customer
2024 was the worst well-recorded year, at 2.6 hours for the average customer. Hatched years have a thin record and are left out of the averages.
Cass, 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 |
|---|---|---|---|---|---|---|
| Aug 9, 2019 | No storm report | 917 | 9% | 17 h | 13 h | 12k |
| May 21, 2024 | Thunderstorms | 935 | 9% | 31 h | 30 h | 7.6k |
| Jul 31, 2024 | Thunderstorms | 390 | 4% | 18 h | – | 5.3k |
| Apr 14, 2023 | No storm report | 962 | 9% | 5.5 h | 5.8 h | 5.3k |
| Dec 15, 2021 | Tornadoes | 1,135 | 11% | 8.0 h | 7.5 h | 4.9k |
| Jun 16, 2017 | Thunderstorms | 958 | 9% | 11 h | 8.5 h | 4.8k |
| Jan 9, 2024 | Winter storm | 993 | 10% | 3.5 h | 3.5 h | 3.4k |
| Jul 30, 2021 | Thunderstorms | 324 | 3% | 10 h | – | 3.0k |
| Jul 7, 2025 | Thunderstorms | 966 | 9% | 3.0 h | 12 min | 2.9k |
| Jul 17, 2017 | No storm report | 117 | 1% | 24 h | – | 2.6k |
| Jul 19, 2016 | Thunderstorms | 973 | 9% | 2.0 h | 1.5 h | 1.9k |
| Sep 5, 2019 | No storm report | 963 | 9% | 2.0 h | 2.0 h | 1.8k |
| Sep 17, 2019 | No storm report | 1,093 | 11% | 6.0 h | 48 min | 1.7k |
| Nov 29, 2022 | No storm report | 971 | 9% | 1.8 h | 1.5 h | 1.7k |
| Jul 1, 2023 | No storm report | 962 | 9% | 1.5 h | 7.5 h | 1.4k |
| Oct 26, 2025 | No storm report | 325 | 3% | 4.8 h | – | 1.3k |
| Oct 11, 2020 | No storm report | 809 | 8% | 2.8 h | 2.2 h | 1.3k |
| Mar 4, 2025 | Winter storm | 379 | 4% | 7.2 h | – | 1.2k |
| Jul 10, 2025 | No storm report | 481 | 5% | 4.5 h | – | 1.2k |
| Aug 18, 2025 | No storm report | 205 | 2% | 6.0 h | – | 1.2k |
| Sep 30, 2021 | No storm report | 416 | 4% | 3.0 h | – | 1.1k |
| May 9, 2016 | No storm report | 717 | 7% | 1.5 h | 7.2 h | 1.0k |
| May 21, 2024 | Thunderstorms | 261 | 3% | 4.5 h | – | 960 |
| May 12, 2024 | No storm report | 510 | 5% | 1.8 h | – | 892 |
| Aug 13, 2025 | No storm report | 245 | 2% | 3.5 h | – | 854 |
| Jul 29, 2025 | No storm report | 918 | 9% | 1.0 h | 8.8 h | 838 |
| May 14, 2020 | No storm report | 536 | 5% | 1.5 h | 1.5 h | 795 |
| May 16, 2024 | No storm report | 510 | 5% | 1.5 h | – | 765 |
| May 24, 2019 | Thunderstorms | 711 | 7% | 1.2 h | 1.0 h | 740 |
| Dec 1, 2021 | No storm report | 967 | 9% | 48 min | 48 min | 724 |
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 Cass from twelve hours before it began to its peak. Matching shows coincidence, not proof of cause.
- No storm on record 58%
- Thunderstorms 29%
- Tornadoes 6.9%
- Winter storm 6.3%
Who keeps the lights on
Utilities serving Cass
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 |
| Southwest Iowa Rural Elec Coop | IA | 122 | 122 | 1.69 | 12.5 | 75k |
| Guthrie County Rural E C A | IA | – | – | – | 10.4 | 72k |
| Farmers Electric Coop, Inc | IA | 90 | 90 | 1.63 | 13.8 | 67k |
| Nishnabotna Valley R E C | IA | 153 | 153 | 1.25 | 13.6 | 64k |
| Atlantic Municipal Utilities | IA | – | – | – | 8.4 | 42k |
| Waverly Municipal Elec Utility | IA | 7 | 7 | 0.14 | 14.1 | 41k |
| City of Anita | IA | – | – | – | – | 4.9k |
| WAPA-- Western Area Power Administration | Federal | – | – | – | – | – |
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
- Adams 8.6 h
- Guthrie 4.2 h
- Audubon 4.0 h
- Pottawattamie 3.0 h
- Shelby 2.9 h
- Montgomery 2.5 h
- Adair 1.4 h
- Cass (this county) 1.3 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 10,329 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 →