County annual report · FIPS 30111
2024 Yellowstone County, MT Power Outage Report
In 2024, customers in Yellowstone County, MT went without power for an average of 3.9 hours, a total of 304K customer-hours (Montana average 8.5 hours). That ranks 30th worst of 51 Montana counties and 1866th of 2,990 nationally.
Compared with MT, the US and 2023
Coverage line is EAGLE-I's share of Montana customers tracked each year.
Biggest outages in Yellowstone County, 2024
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | August 6, 2024 19:45 | August 12, 2024 16:30 | 5d 20h | 14,848 | 127K |
| 2 | February 7, 2024 11:30 | February 7, 2024 18:15 | 6h 45m | 6,265 | 33K |
| 3 | March 2, 2024 23:15 | March 3, 2024 03:00 | 3h 45m | 6,261 | 16K |
| 4 | November 20, 2024 14:45 | November 22, 2024 02:45 | 1d 12h | 5,383 | 7,851 |
| 5 | August 5, 2024 01:30 | August 5, 2024 08:45 | 7h 15m | 3,656 | 8,282 |
| 6 | October 17, 2024 15:45 | October 17, 2024 21:15 | 5h 30m | 2,819 | 3,771 |
| 7 | June 28, 2024 14:00 | June 29, 2024 06:30 | 16h 30m | 2,299 | 8,511 |
| 8 | April 4, 2024 19:15 | April 4, 2024 22:30 | 3h 15m | 1,999 | 2,500 |
| 9 | December 8, 2024 02:30 | December 8, 2024 04:00 | 1h 30m | 1,907 | 2,383 |
| 10 | July 6, 2024 12:45 | July 6, 2024 17:30 | 4h 45m | 1,836 | 3,676 |
Outage episodes by size in 2024: 74 reached 100+ customers, 16 reached 1,000+ customers, 1 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 Yellowstone County reported on EIA Form 861 for 2024, 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) | 2024 | 3.9 hrs | 1.30 | 2.0 hrs | 0.95 |
| Mid-Yellowstone Elec Coop, Inc | 2018 | 4.5 hrs | 3.82 | 4.5 hrs | 3.82 |
| WAPA-- Western Area Power Administration | - | - | - | - | - |
| NorthWestern Energy | - | - | - | - | - |
| Fergus Electric Coop, Inc | - | - | - | - | - |
| Yellowstone Valley Elec Co-op | - | - | - | - | - |
About this data
- Outage figures come from DOE/ORNL EAGLE-I, which records customers out by county every 15 minutes. EAGLE-I tracked about n/a of Montana's customers in 2024; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 77,606 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. Yellowstone County has data for 2019–2025.
Cite this report
MassOutage (massoutage.com), Yellowstone County, MT annual power outage report, 2024, 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/2024/montana/yellowstone-county