Johnson County Power Outage History
2017–2025 · Wyoming
Better than average — fewer or shorter outages than most counties. How grades are calculated
Outages by year
Outages by month (seasonality)
Worst outage events on record
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| Aug 12, 2022 | <1 hr | 3,889 (57%) | Unnamed event |
| Oct 23, 2018 | <1 hr | 3,638 (54%) | Unnamed event |
| May 31, 2018 | 4 hrs | 3,618 (53%) | Flood |
| Jan 6, 2018 | <1 hr | 3,617 (53%) | Unnamed event |
| Mar 23, 2018 | <1 hr | 3,611 (53%) | Unnamed event |
Over the 9 years from 2017 to 2025, Johnson County recorded 532 distinct power outage events, averaging 2.2 hours per event.
The single worst outage on record in Johnson County started August 12, 2022, lasting less than 1 hour and leaving up to 3,889 customers without power (57% of the county) at its peak.
August has historically been the worst month for outages in Johnson County, with 82 events recorded during that month across the dataset.
Based on this history, Johnson County earns a Reliability Grade of B, placing it in the 69th percentile nationally for grid reliability (higher percentile = more reliable).
Sized for Johnson County's outage profile
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Outage-prep kit
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Similar counties in Wyoming
Counties with the closest reliability grade and national percentile to Johnson County.
| County | Grade | National percentile |
|---|---|---|
| Albany County | B | 71st |
| Sublette County | B | 64th |
| Hot Springs County | B | 73rd |
| Weston County | B | 64th |
| Carbon County | B | 75th |
Most reliable counties in Wyoming
The top 3 counties in Wyoming by reliability grade and percentile.
| County | Grade | National percentile |
|---|---|---|
| Teton County | A | 97th |
| Fremont County | A | 94th |
| Niobrara County | A | 93rd |
Least reliable counties in Wyoming
The bottom 3 counties in Wyoming by reliability grade and percentile.
| County | Grade | National percentile |
|---|---|---|
| Crook County | C | 41st |
| Converse County | C | 48th |
| Weston County | B | 64th |
Most reliable counties nationally
The top 3 counties nationally by reliability grade and percentile.
| County | State | Grade | National percentile |
|---|---|---|---|
| Clay County | South Dakota | A | 100th |
| Clearwater County | Minnesota | A | 99th |
| Limestone County | Alabama | A | 99th |
Least reliable counties nationally
The bottom 3 counties nationally by reliability grade and percentile.
| County | State | Grade | National percentile |
|---|---|---|---|
| Clay County | West Virginia | F | 0th |
| Lincoln County | West Virginia | F | 0th |
| Cameron Parish | Louisiana | F | 0th |
FAQ
How often does power go out in Johnson County?
Between 2017 and 2025, Johnson County recorded 532 outage events, averaging 2.2 hours each.
What is Johnson County's reliability grade?
Johnson County has a Reliability Grade of B, in the 69th national percentile.
What was the worst power outage in Johnson County?
The worst outage on record started August 12, 2022, lasting less than 1 hour and affecting up to 3,889 customers.