PowerOutageHistory
Reliability Grade
C
Average
2015-2025
Iowa

Mills CountyPower Outage History

20152025 · Iowa
Share

What this grade means

Average — typical outage frequency and duration nationally. This county sits in the middle of the national distribution — its outage frequency and duration over the past 12 years are close to the nationwide median, neither notably better nor worse than most other US counties. A typical amount of backup-power preparedness is reasonable here.

Takeaway
Typical outage risk
Reliability Rank
Fuller bar = more reliable
Nationwide49th pct
In Iowa#77 of 99
See full Iowa rankings →
Total events
354
Recorded 2015–2025
Avg duration
2.6 hrs
Per outage event
Longest outage
68 hrs
Single worst event on record
Customers served
8,157
Utility customers in county

Outages by year

Outages by month (seasonality)

Worst outage events on record

DateDurationCustomers affectedCause
Jan 21, 20186 hrs6,702 (82%)Unnamed event
Dec 15, 202168 hrs5,353 (66%)High Wind
Jun 17, 201742 hrs3,779 (46%)Hail
Jun 15, 202214 hrs2,540 (31%)Hail
Jul 7, 20166 hrs2,514 (31%)Unnamed event

Was There an Outage on a Specific Date?

Pick a date to see whether a power outage was recorded for Mills County, Iowa that day.

Over the 11 years from 2015 to 2025, Mills County recorded 354 distinct power outage events, averaging 2.6 hours per event.

The single worst outage on record in Mills County started January 21, 2018, lasting 6 hours and leaving up to 6,702 customers without power (82% of the county) at its peak.

June has historically been the worst month for outages in Mills County, with 47 events recorded during that month across the dataset.

Based on this history, Mills County earns a Reliability Grade of C, placing it in the 49th percentile nationally for grid reliability (higher percentile = more reliable).

Similar counties in Iowa

Counties with the closest reliability grade and national percentile to Mills County.

CountyGradeNational percentile
Scott CountyC50th
Hancock CountyC48th
Appanoose CountyC48th
Keokuk CountyC51st
Washington CountyC47th

Most reliable counties nationally

The top 3 counties nationally by reliability grade and percentile.

CountyStateGradeNational percentile
Clay CountySouth DakotaA100th
Clearwater CountyMinnesotaA99th
Limestone CountyAlabamaA99th

Least reliable counties nationally

The bottom 3 counties nationally by reliability grade and percentile.

FAQ

How often does power go out in Mills County?

Between 2015 and 2025, Mills County recorded 354 outage events, averaging 2.6 hours each.

What is Mills County's reliability grade?

Mills County has a Reliability Grade of C, in the 49th national percentile.

What was the worst power outage in Mills County?

The worst outage on record started January 21, 2018, lasting 6 hours and affecting up to 6,702 customers.

Share
Data: ORNL EAGLE-I Recorded Electricity Outages (2014–2025), CC BY 4.0. Storm names: NOAA Storm Events Database. Last data refresh: 2025. See methodology.