County annual report · FIPS 56019
2021 Johnson County, WY Power Outage Report
In 2021, customers in Johnson County, WY went without power for an average of 3.6 hours, a total of 20K customer-hours (Wyoming average 2.2 hours). That ranks 8th worst of 20 Wyoming counties and 1660th of 2,974 nationally.
Compared with WY, the US and 2020
Coverage line is EAGLE-I's share of Wyoming customers tracked each year.
Biggest outages in Johnson County, 2021
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | June 22, 2021 18:00 | June 22, 2021 22:15 | 4h 15m | 1,236 | 798 |
| 2 | June 17, 2021 15:30 | June 17, 2021 15:45 | 15m | 1,044 | 261 |
| 3 | November 24, 2021 21:15 | November 24, 2021 21:30 | 15m | 1,043 | 261 |
| 4 | April 9, 2021 00:30 | April 9, 2021 17:45 | 17h 15m | 785 | 1,875 |
| 5 | August 26, 2021 16:30 | August 26, 2021 17:30 | 1h | 515 | 268 |
| 6 | June 3, 2021 15:15 | June 3, 2021 22:00 | 6h 45m | 510 | 1,773 |
| 7 | June 1, 2021 14:30 | June 1, 2021 14:45 | 15m | 500 | 125 |
| 8 | April 10, 2021 02:30 | April 10, 2021 05:15 | 2h 45m | 460 | 562 |
| 9 | March 15, 2021 19:30 | March 15, 2021 20:00 | 30m | 426 | 111 |
| 10 | March 10, 2021 14:45 | March 10, 2021 15:00 | 15m | 408 | 102 |
Outage episodes by size in 2021: 42 reached 100+ customers, 3 reached 1,000+ customers, 0 reached 10,000+ customers.
Utility reliability filed with the EIA
SAIDI (average outage time per customer) and SAIFI (average interruptions per customer) that utilities serving Johnson County reported on EIA Form 861 for 2021, or their most recent earlier filing. Utility-wide figures, not county-specific.
| Utility | EIA year | SAIDI | SAIFI | SAIDI excl. major events | SAIFI excl. major events |
|---|---|---|---|---|---|
| PacifiCorp | 2021 | 4.3 hrs | 1.86 | 2.0 hrs | 1.19 |
| Powder River Energy Corp | 2021 | 5.4 hrs | 2.15 | 3.9 hrs | 1.91 |
| Big Horn Rural Electric Co | 2018 | 4.0 hrs | 1.80 | - | - |
| Montana-Dakota Utilities Co | - | - | - | - | - |
| High Plains Power Inc | - | - | - | - | - |
About this data
- Outage figures come from DOE/ORNL EAGLE-I, which records customers out by county every 15 minutes. EAGLE-I tracked about 71% of Wyoming's customers in 2021; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 5,448 customers (ORNL modeled county customer count), including major storm days. It is comparable across counties but is not the SAIDI a utility files.
- An outage event is a continuous stretch with customers out; counts at 100, 1,000 and 10,000+ use its peak.
- Years loaded: 2015–2025. Johnson County has data for 2017–2025.
Cite this report
MassOutage (massoutage.com), Johnson County, WY annual power outage report, 2021, data as of Oct 3, 2026 02:41 UTC, sources: DOE EAGLE-I (https://eagle-i.doe.gov/); EAGLE-I modeled customer counts (MCC) (https://figshare.com/); EIA Form 861 (utility reliability) (https://www.eia.gov/electricity/data/eia861/). https://massoutage.com/reports/2021/wyoming/johnson-county