PowerOutageHistory
Reliability Grade
F
Least reliable
2014-2025
Iowa

Marshall CountyPower Outage History

20142025 · Iowa
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What this grade means

Bottom 20% least reliable nationally — frequent and/or long outages. This county ranks in the least reliable fifth of all US counties in our dataset: some combination of frequent outages, long restoration times, or customers affected puts it near the bottom nationally. Backup power is worth prioritizing here rather than treating it as optional.

Takeaway
High outage risk
Reliability Rank
Fuller bar = more reliable
Nationwide6th pct
In IowaLeast reliable of 99
See full Iowa rankings →
Total events
450
Recorded 2014–2025
Avg duration
3.7 hrs
Per outage event
Longest outage
213 hrs
Single worst event on record
Customers served
17,461
Utility customers in county

Outages by year

Outages by month (seasonality)

Worst outage events on record

DateDurationCustomers affectedCause
Aug 10, 2020213 hrs16,662 (95%)Tornado
Feb 19, 20161 hrs11,052 (63%)High Wind
Jul 19, 201878 hrs8,657 (50%)Tornado
Nov 1, 20177 hrs7,750 (44%)Frost/Freeze
Nov 6, 2017<1 hr7,442 (43%)Unnamed event

Was There an Outage on a Specific Date?

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

Over the 12 years from 2014 to 2025, Marshall County recorded 450 distinct power outage events, averaging 3.7 hours per event.

The single worst outage on record in Marshall County started August 10, 2020 (Tornado), lasting 213 hours and leaving up to 16,662 customers without power (95% of the county) at its peak.

June has historically been the worst month for outages in Marshall County, with 52 events recorded during that month across the dataset.

Based on this history, Marshall County earns a Reliability Grade of F, placing it in the 6th percentile nationally for grid reliability (higher percentile = more reliable).

Similar counties in Iowa

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

CountyGradeNational percentile
Tama CountyF12th
Jasper CountyF14th
Poweshiek CountyF15th
Linn CountyF16th
Benton CountyF18th

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 Marshall County?

Between 2014 and 2025, Marshall County recorded 450 outage events, averaging 3.7 hours each.

What is Marshall County's reliability grade?

Marshall County has a Reliability Grade of F, in the 6th national percentile.

What was the worst power outage in Marshall County?

The worst outage on record started August 10, 2020 (Tornado), lasting 213 hours and affecting up to 16,662 customers.

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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.