PowerOutageHistory
Reliability Grade
F
Least reliable
2015-2025
Idaho

Boise CountyPower Outage History

20152025 · Idaho
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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
Nationwide14th pct
In Idaho#42 of 44
See full Idaho rankings →
Total events
686
Recorded 2015–2025
Avg duration
4.4 hrs
Per outage event
Longest outage
455 hrs
Single worst event on record
Customers served
11,045
Utility customers in county

Outages by year

Outages by month (seasonality)

Worst outage events on record

DateDurationCustomers affectedCause
Sep 16, 2021<1 hr11,045 (100%)Unnamed event
Jul 24, 202424 hrs9,796 (89%)Unnamed event
Jan 16, 20245 hrs5,093 (46%)Heavy Snow
May 13, 20227 hrs4,970 (45%)Unnamed event
Oct 27, 20212 hrs4,647 (42%)Unnamed event

Was There an Outage on a Specific Date?

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

Over the 11 years from 2015 to 2025, Boise County recorded 686 distinct power outage events, averaging 4.4 hours per event.

The single worst outage on record in Boise County started September 16, 2021, lasting less than 1 hour and leaving up to 11,045 customers without power (100% of the county) at its peak.

December has historically been the worst month for outages in Boise County, with 69 events recorded during that month across the dataset.

Based on this history, Boise County earns a Reliability Grade of F, placing it in the 14th percentile nationally for grid reliability (higher percentile = more reliable).

Similar counties in Idaho

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

CountyGradeNational percentile
Benewah CountyF17th
Boundary CountyF17th
Idaho CountyF17th
Bonner CountyF10th
Shoshone CountyD21st

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 Boise County?

Between 2015 and 2025, Boise County recorded 686 outage events, averaging 4.4 hours each.

What is Boise County's reliability grade?

Boise County has a Reliability Grade of F, in the 14th national percentile.

What was the worst power outage in Boise County?

The worst outage on record started September 16, 2021, lasting less than 1 hour and affecting up to 11,045 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.