PowerOutageHistory
Reliability Grade
C
Average
2015-2025
Tennessee

Grainger CountyPower Outage History

20152025 · Tennessee
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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 Tennessee#58 of 83
See full Tennessee rankings →
Total events
626
Recorded 2015–2025
Avg duration
2.7 hrs
Per outage event
Longest outage
86 hrs
Single worst event on record
Customers served
13,739
Utility customers in county

Outages by year

Outages by month (seasonality)

Worst outage events on record

DateDurationCustomers affectedCause
Sep 27, 202486 hrs5,826 (42%)Tropical Storm Helene
Dec 23, 20222 hrs4,225 (31%)Winter Storm Elliott
May 2, 20242 hrs3,908 (28%)Unnamed event
Dec 24, 20222 hrs2,781 (20%)Winter Storm Elliott
May 8, 20245 hrs2,741 (20%)Hail

Was There an Outage on a Specific Date?

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

Over the 11 years from 2015 to 2025, Grainger County recorded 626 distinct power outage events, averaging 2.7 hours per event.

The single worst outage on record in Grainger County started September 27, 2024 (Tropical Storm Helene), lasting 86 hours and leaving up to 5,826 customers without power (42% of the county) at its peak.

June has historically been the worst month for outages in Grainger County, with 70 events recorded during that month across the dataset.

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

Similar counties in Tennessee

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

CountyGradeNational percentile
Bradley CountyC47th
Cheatham CountyC46th
Cumberland CountyC52nd
Knox CountyC52nd
Blount CountyC52nd

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 Grainger County?

Between 2015 and 2025, Grainger County recorded 626 outage events, averaging 2.7 hours each.

What is Grainger County's reliability grade?

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

What was the worst power outage in Grainger County?

The worst outage on record started September 27, 2024 (Tropical Storm Helene), lasting 86 hours and affecting up to 5,826 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.