Power Out Map
– 0% of Johnson out 0 customers out in Wyoming

Power outage history

Johnson County Wyoming

5.5hours

without power for the average customer in a typical year, 2018–2025

4th most of 20 in Wyoming 17% below the national median

Worst outage on record Nov 13, 2025 100% of customers out · 90% back in 4.0 hours
Hours without power, average customer per year 5.5h / yr State average 2.4 h · national median 6.6 h
Major outages a year 3.9 Peaks over 10% of customers or 50,000 customers
Typical time to restore 90% 2hours Median across major outages, from the peak
Longest single outage 48hours Mar 28, 2020, over 1% of customers out
Outage hours on storm days 17% Share falling on days with a NOAA storm report here
Worst year 2020 9.8 hours without power, average customer
Electricity customers 5,448 ORNL customer model · 8 well-covered years

Every day since 2015

Eleven years, one night at a time

Each cell is a day. The brighter it is, the larger the share of Johnson's customers who were without power at that day's worst moment.

20152016201720182019202020212022202320242025
0%100% of customers out

Year by year

Hours in the dark, per customer

2020 was the worst well-recorded year, at 9.8 hours for the average customer. Hatched years have a thin record and are left out of the averages.

Johnson, hours without power per customer

JohnsonUS median countyWyoming average
0 2 4 6 8 10 12 0.3 ’17 2.9 ’18 1.7 ’19 9.8 ’20 3.5 ’21 5.3 ’22 4.3 ’23 7.0 ’24 9.1 ’25 US 6.6 WY 2.4

The record

The biggest outages since 2015

Ranked by customer-hours lost: customers out multiplied by how long they stayed out. Times are local.

Began Storm Peak out Share Lasted 90% restored Customer-hours
Nov 13, 2025 No storm report 5,448 100% 9.0 h 4.0 h 20k
May 31, 2018 No storm report 3,618 66% 4.2 h 1.0 h 12k
Mar 28, 2020 No storm report 219 4% 48 h – 10k
Sep 9, 2020 No storm report 1,052 19% 6.5 h 6.5 h 6.8k
Oct 27, 2020 No storm report 1,079 20% 6.2 h 6.2 h 6.7k
Jun 6, 2024 No storm report 1,200 22% 4.8 h 6.5 h 5.7k
Dec 19, 2025 Windstorm 855 16% 14 h 3.8 h 5.0k
Sep 7, 2020 No storm report 1,031 19% 4.5 h 4.8 h 4.6k
Oct 14, 2020 No storm report 687 13% 7.2 h 6.2 h 3.9k
Jun 23, 2023 Tornadoes 851 16% 7.5 h 4.2 h 3.8k
Sep 12, 2024 No storm report 384 7% 24 h 12 min 3.7k
Aug 6, 2022 No storm report 709 13% 8.2 h 6.2 h 3.7k

After the peak

How fast the lights come back

Each line is one major outage, from its peak. The amber line is the typical path.

0% 25% 50% 75% 100% peak+24h+48h+72h+96h half back by +6h 90% by +6h

When it happens

The outage clock

Customer-hours out by month (rings, January innermost) and local hour, 2018–2025.

00061218 Jan inside

What was happening

Weather behind the outages

Each outage is matched to NOAA storm reports for Johnson from twelve hours before it began to its peak. Matching shows coincidence, not proof of cause.

  • No storm on record 83%
  • Windstorm 7.1%
  • Winter storm 6.0%
  • Tornadoes 1.9%
  • Thunderstorms 0.8%

Who keeps the lights on

Utilities serving Johnson

As each utility reports to the Energy Information Administration for its whole Wyoming territory, not this county alone. Outage minutes include major storm days.

Utility Type Outage min / yr Excl. major storms Outages / yr Residential ¢/kWh Customers
PacifiCorp Investor Owned 195 91 1.37 15.1 119k
Big Horn Rural Electric Co WY 208 – 1.29 14.9 31k
Powder River Energy Corp Cooperative 571 271 3.50 12.2 16k
Montana-Dakota Utilities Co Investor Owned 354 134 1.80 12.0 15k
High Plains Power Inc Cooperative 320 263 – 14.2 13k

EIA Form 861, latest year each utility reported. Outage minutes are SAIDI, the yearly minutes the average customer goes without power; outages a year are SAIFI.

Next door

Neighbouring counties

Across Wyoming

Where it is darkest

Hours / yr64+

All Wyoming counties →

About these numbers

Notes

Outages come from the EAGLE-I record of utility outage maps collected every 15 minutes by Oak Ridge National Laboratory. Hours without power are customer-hours divided by the county's 5,448 electricity customers. Averages use well-covered years from 2018. Outages shorter than 15 minutes, and utilities that publish no outage map, are not in the record, so these figures understate the total. How every number is made →