County annual report · FIPS 30009
2021 Carbon County, MT Power Outage Report
In 2021, customers in Carbon County, MT went without power for an average of 8.1 hours, a total of 53K customer-hours (Montana average 5.0 hours). That ranks 17th worst of 51 Montana counties and 927th of 2,974 nationally.
Compared with MT, the US and 2020
Coverage line is EAGLE-I's share of Montana customers tracked each year.
Biggest outages in Carbon 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 | November 16, 2021 04:45 | November 17, 2021 09:45 | 1d 5h | 1,329 | 14K |
| 2 | June 18, 2021 23:45 | June 19, 2021 02:45 | 3h | 1,291 | 2,259 |
| 3 | June 3, 2021 23:45 | June 4, 2021 08:30 | 8h 45m | 984 | 3,696 |
| 4 | August 11, 2021 15:45 | August 11, 2021 17:15 | 1h 30m | 963 | 845 |
| 5 | May 20, 2021 01:45 | May 20, 2021 11:45 | 10h | 790 | 5,496 |
| 6 | May 26, 2021 08:00 | May 26, 2021 12:30 | 4h 30m | 536 | 1,536 |
| 7 | March 29, 2021 04:00 | March 31, 2021 00:30 | 1d 20h | 499 | 5,269 |
| 8 | March 11, 2021 19:00 | March 11, 2021 20:30 | 1h 30m | 452 | 678 |
| 9 | February 18, 2021 15:30 | February 18, 2021 17:15 | 1h 45m | 449 | 786 |
| 10 | April 5, 2021 03:45 | April 5, 2021 11:15 | 7h 30m | 449 | 1,158 |
Outage episodes by size in 2021: 24 reached 100+ customers, 2 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 Carbon 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 |
|---|---|---|---|---|---|
| NorthWestern Energy LLC - (MT) | 2021 | 2.5 hrs | 1.37 | 2.1 hrs | 1.18 |
| Big Horn Rural Electric Co | 2018 | 4.0 hrs | 1.80 | - | - |
| Flathead Electric Coop Inc | 2021 | 11.2 hrs | 2.62 | 2.7 hrs | 1.97 |
| WAPA-- Western Area Power Administration | - | - | - | - | - |
| NorthWestern Energy | - | - | - | - | - |
| Yellowstone Valley Elec Co-op | - | - | - | - | - |
| Beartooth Electric Coop, 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 76% of Montana's customers in 2021; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 6,512 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. Carbon County has data for 2016, 2018–2025.
Cite this report
MassOutage (massoutage.com), Carbon County, MT 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/montana/carbon-county