Power Out Map
– 0% of Clarke out 0 customers out in Iowa

Power outage history

Clarke County Iowa

1.9hours

without power for the average customer in a typical year, 2018–2025

83rd most of 98 in Iowa 72% below the national median

Worst outage on record Dec 15, 2021 16% of customers out · 90% back in 36 hours
Hours without power, average customer per year 1.9h / yr State average 5.4 h · national median 6.6 h
Major outages a year 1.3 Peaks over 10% of customers or 50,000 customers
Typical time to restore 90% 4hours Median across major outages, from the peak
Longest single outage 35hours Dec 15, 2021, over 1% of customers out
Outage hours on storm days 31% Share falling on days with a NOAA storm report here
Worst year 2024 2.7 hours without power, average customer
Electricity customers 4,290 ORNL customer model · 8 well-covered years

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 Clarke's customers who were without power at that day's worst moment.

20152016201720182019202020212022202320242025
0%100% of customers out

Year by year

Hours in the dark, per customer

2024 was the worst well-recorded year, at 2.7 hours for the average customer. Hatched years have a thin record and are left out of the averages.

Clarke, hours without power per customer

ClarkeUS median countyIowa average
0 2 4 6 8 3.1 ’15 0.8 ’16 2.1 ’17 1.9 ’18 2.3 ’19 1.1 ’20 2.6 ’21 1.0 ’22 1.6 ’23 2.7 ’24 1.6 ’25 US 6.6 IA 5.4

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 Thunderstorms 693 16% 35 h 36 h 6.8k
May 17, 2015 Thunderstorms 1,131 26% 12 h 11 h 6.8k
Jun 28, 2017 No storm report 889 21% 10 h 8.8 h 6.1k
Oct 30, 2019 No storm report 481 11% 8.0 h 8.0 h 3.0k
Jun 28, 2018 Thunderstorms 1,254 29% 5.2 h 4.8 h 2.8k
Sep 12, 2024 No storm report 746 17% 3.0 h 9.0 h 2.2k
Aug 13, 2023 No storm report 507 12% 29 h 3.0 h 2.1k
Aug 4, 2024 No storm report 212 5% 9.0 h – 1.8k
May 19, 2024 No storm report 208 5% 14 h – 1.7k
Nov 26, 2015 No storm report 514 12% 3.2 h 5.8 h 1.6k
Aug 10, 2020 Thunderstorms 82 2% 19 h – 1.5k
Aug 20, 2018 No storm report 48 1% 28 h – 1.3k

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.

0% 25% 50% 75% 100% peak+24h+48h+72h+96h half back by +2h 90% by +4h

When it happens

The outage clock

Customer-hours out by month (rings, January innermost) and local hour, 2018–2025.

00061218 Jan inside

What was happening

Weather behind the outages

Each outage is matched to NOAA storm reports for Clarke from twelve hours before it began to its peak. Matching shows coincidence, not proof of cause.

  • No storm on record 69%
  • Thunderstorms 30%
  • Winter storm 1.0%

Who keeps the lights on

Utilities serving Clarke

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
Interstate Power and Light Co Investor Owned 89 74 0.82 17.8 419k
Clarke Electric Coop Inc IA 113 96 1.33 13.4 69k

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

Across Iowa

Where it is darkest

Hours / yr64+

All Iowa counties →

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 4,290 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 →