PowerOutageHistory
Reliability Grade
A
Top tier
2014-2025
Iowa

Union CountyPower Outage History

20142025 · Iowa
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What this grade means

Top 20% most reliable nationally — infrequent, short outages. This county ranks in the most reliable fifth of all US counties in our dataset, based on 12 years of real DOE outage records: outages happen less often here, and when they do occur they tend to be resolved quickly compared to the rest of the country. Baseline outage risk is low, though a severe local storm can still occasionally cause a longer-than-usual outage regardless of the long-term track record.

Takeaway
Low outage risk
Reliability Rank
Fuller bar = more reliable
Nationwide87th pct
In Iowa#14 of 99
See full Iowa rankings →
Total events
467
Recorded 2014–2025
Avg duration
1.4 hrs
Per outage event
Longest outage
26 hrs
Single worst event on record
Customers served
7,985
Utility customers in county

Outages by year

Outages by month (seasonality)

Worst outage events on record

DateDurationCustomers affectedCause
May 24, 20192 hrs5,453 (68%)Unnamed event
Jun 8, 202211 hrs3,046 (38%)Thunderstorm Wind
Oct 22, 2024<1 hr1,911 (24%)Unnamed event
May 28, 20181 hrs1,897 (24%)Unnamed event
Aug 23, 2018<1 hr1,895 (24%)Heavy Rain

Was There an Outage on a Specific Date?

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

Over the 12 years from 2014 to 2025, Union County recorded 467 distinct power outage events, averaging 1.4 hours per event.

The single worst outage on record in Union County started May 24, 2019, lasting 2 hours and leaving up to 5,453 customers without power (68% of the county) at its peak.

June has historically been the worst month for outages in Union County, with 67 events recorded during that month across the dataset.

Based on this history, Union County earns a Reliability Grade of A, placing it in the 87th percentile nationally for grid reliability (higher percentile = more reliable).

Similar counties in Iowa

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

CountyGradeNational percentile
Cherokee CountyA87th
Jackson CountyA87th
Buena Vista CountyA87th
Plymouth CountyA88th
Osceola CountyA88th

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 Union County?

Between 2014 and 2025, Union County recorded 467 outage events, averaging 1.4 hours each.

What is Union County's reliability grade?

Union County has a Reliability Grade of A, in the 87th national percentile.

What was the worst power outage in Union County?

The worst outage on record started May 24, 2019, lasting 2 hours and affecting up to 5,453 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.