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

Power outage history

Calhoun County Iowa

6.8hours

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

17th most of 98 in Iowa close to the national median

Worst outage on record Mar 19, 2025 69% of customers out · 90% back in 18 hours
Hours without power, average customer per year 6.8h / yr State average 5.4 h · national median 6.6 h
Major outages a year 4.8 Peaks over 10% of customers or 50,000 customers
Typical time to restore 90% 2hours Median across major outages, from the peak
Longest single outage 33hours May 16, 2017, over 1% of customers out
Outage hours on storm days 69% Share falling on days with a NOAA storm report here
Worst year 2021 15 hours without power, average customer
Electricity customers 4,092 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 Calhoun'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

2021 was the worst well-recorded year, at 15 hours for the average customer. Hatched years have a thin record and are left out of the averages.

Calhoun, hours without power per customer

CalhounUS median countyIowa average
0 5 10 15 20 ’15 6.4 ’16 4.4 ’17 7.9 ’18 2.9 ’19 2.2 ’20 15 ’21 4.6 ’22 1.4 ’23 7.2 ’24 13 ’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
Mar 19, 2025 Winter storm 2,838 69% 31 h 18 h 25k
Apr 14, 2018 Winter storm 2,152 53% 25 h 20 h 24k
May 24, 2024 Thunderstorms 2,439 60% 18 h 16 h 24k
Dec 15, 2021 Tornadoes 2,249 55% 30 h 21 h 19k
Jul 14, 2021 Tornadoes 1,320 32% 15 h 12 h 18k
Mar 4, 2025 Winter storm 748 18% 26 h 13 h 11k
Nov 26, 2015 Ice storm 2,026 50% 14 h 2.5 h 11k
Dec 10, 2021 Winter storm 2,353 57% 18 h 13 h 10k
Nov 29, 2022 No storm report 1,592 39% 5.0 h 14 h 8.0k
Jul 27, 2016 No storm report 1,396 34% 6.5 h 6.2 h 7.7k
Jan 26, 2021 Winter storm 1,079 26% 5.8 h 5.8 h 6.2k
Mar 27, 2025 No storm report 1,586 39% 5.5 h 4.8 h 6.1k

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 +4h 90% by +14h

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 Calhoun from twelve hours before it began to its peak. Matching shows coincidence, not proof of cause.

  • Winter storm 37%
  • No storm on record 31%
  • Tornadoes 18%
  • Thunderstorms 13%
  • Windstorm 1.0%

Who keeps the lights on

Utilities serving Calhoun

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
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
Midland Power Coop Cooperative 488 91 1.79 13.7 12k
City of Farnhamville IA – – – – 1.8k

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 4,092 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 →