PowerOutageHistory
Reliability Grade
F
Least reliable
2014-2025
Michigan

Iosco CountyPower Outage History

20142025 · Michigan
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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
Nationwide3rd pct
In Michigan#77 of 82
See full Michigan rankings →
Total events
773
Recorded 2014–2025
Avg duration
5.3 hrs
Per outage event
Longest outage
106 hrs
Single worst event on record
Customers served
14,364
Utility customers in county

Outages by year

Outages by month (seasonality)

Worst outage events on record

DateDurationCustomers affectedCause
Jul 19, 202055 hrs9,443 (66%)Thunderstorm Wind
Apr 29, 202532 hrs8,777 (61%)Unnamed event
Nov 5, 202220 hrs7,660 (53%)Unnamed event
Nov 6, 202259 hrs7,026 (49%)Unnamed event
Dec 16, 202182 hrs6,309 (44%)High Wind

Was There an Outage on a Specific Date?

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

Over the 12 years from 2014 to 2025, Iosco County recorded 773 distinct power outage events, averaging 5.3 hours per event.

The single worst outage on record in Iosco County started July 19, 2020 (Thunderstorm Wind), lasting 55 hours and leaving up to 9,443 customers without power (66% of the county) at its peak.

June has historically been the worst month for outages in Iosco County, with 94 events recorded during that month across the dataset.

Based on this history, Iosco County earns a Reliability Grade of F, placing it in the 3rd percentile nationally for grid reliability (higher percentile = more reliable).

Similar counties in Michigan

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

CountyGradeNational percentile
Arenac CountyF3rd
Cheboygan CountyF3rd
Otsego CountyF4th
Crawford CountyF4th
Clare CountyF2nd

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 Iosco County?

Between 2014 and 2025, Iosco County recorded 773 outage events, averaging 5.3 hours each.

What is Iosco County's reliability grade?

Iosco County has a Reliability Grade of F, in the 3rd national percentile.

What was the worst power outage in Iosco County?

The worst outage on record started July 19, 2020 (Thunderstorm Wind), lasting 55 hours and affecting up to 9,443 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.