PowerOutageHistory
Reliability Grade
D
Worse than average
2015-2025
Tennessee

Union CountyPower Outage History

20152025 · Tennessee
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What this grade means

Worse than average — more frequent or longer outages than most counties. This county's recorded history shows more frequent outages and/or longer restoration times than most US counties over the same 12-year period. If you live here, it's worth taking backup power more seriously than an average household would.

Takeaway
Higher-than-average outage risk
Reliability Rank
Fuller bar = more reliable
Nationwide32nd pct
In Tennessee#74 of 83
See full Tennessee rankings →
Total events
1,158
Recorded 2015–2025
Avg duration
2.5 hrs
Per outage event
Longest outage
57 hrs
Single worst event on record
Customers served
11,905
Utility customers in county

Outages by year

Outages by month (seasonality)

Worst outage events on record

DateDurationCustomers affectedCause
Mar 13, 2020<1 hr8,591 (72%)Unnamed event
May 14, 2019<1 hr8,582 (72%)Unnamed event
May 14, 2019<1 hr8,582 (72%)Unnamed event
Jul 21, 20184 hrs8,546 (72%)Thunderstorm Wind
Jul 31, 20167 hrs7,509 (63%)Unnamed event

Was There an Outage on a Specific Date?

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

Over the 11 years from 2015 to 2025, Union County recorded 1,158 distinct power outage events, averaging 2.5 hours per event.

The single worst outage on record in Union County started March 13, 2020, lasting less than 1 hour and leaving up to 8,591 customers without power (72% of the county) at its peak.

July has historically been the worst month for outages in Union County, with 145 events recorded during that month across the dataset.

Based on this history, Union County earns a Reliability Grade of D, placing it in the 32nd percentile nationally for grid reliability (higher percentile = more reliable).

Similar counties in Tennessee

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

CountyGradeNational percentile
Giles CountyD33rd
Polk CountyD33rd
Fentress CountyD33rd
Macon CountyD31st
Tipton CountyD30th

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 2015 and 2025, Union County recorded 1,158 outage events, averaging 2.5 hours each.

What is Union County's reliability grade?

Union County has a Reliability Grade of D, in the 32nd national percentile.

What was the worst power outage in Union County?

The worst outage on record started March 13, 2020, lasting less than 1 hour and affecting up to 8,591 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.