County annual report · FIPS 30097
2025 Sweet Grass County, MT Power Outage Report
In 2025, customers in Sweet Grass County, MT went without power for an average of 11.4 hours, a total of 23K customer-hours (Montana average 6.8 hours). That ranks 15th worst of 51 Montana counties and 702nd of 3,000 nationally.
Compared with MT, the US and 2024
Coverage line is EAGLE-I's share of Montana customers tracked each year.
Biggest outages in Sweet Grass County, 2025
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | December 17, 2025 18:15 | December 20, 2025 18:15 | 3d | 1,612 | 12K |
| 2 | December 9, 2025 10:00 | December 10, 2025 04:00 | 18h | 817 | 3,181 |
| 3 | April 17, 2025 12:45 | April 17, 2025 19:00 | 6h 15m | 513 | 2,206 |
| 4 | October 14, 2025 16:00 | October 14, 2025 17:45 | 1h 45m | 306 | 536 |
| 5 | October 22, 2025 16:45 | October 22, 2025 18:15 | 1h 30m | 263 | 395 |
| 6 | February 11, 2025 13:15 | February 11, 2025 17:30 | 4h 15m | 262 | 525 |
| 7 | June 17, 2025 01:00 | June 17, 2025 03:15 | 2h 15m | 261 | 393 |
| 8 | March 27, 2025 22:30 | March 28, 2025 00:45 | 2h 15m | 243 | 547 |
| 9 | June 2, 2025 10:45 | June 2, 2025 14:45 | 4h | 230 | 920 |
| 10 | May 14, 2025 17:45 | May 14, 2025 20:45 | 3h | 112 | 151 |
Outage episodes by size in 2025: 11 reached 100+ customers, 1 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 Sweet Grass County reported on EIA Form 861 for 2025, 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 |
| Fergus Electric Coop, Inc | - | - | - | - | - |
| Beartooth Electric Coop, Inc | - | - | - | - | - |
| Park 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 n/a of Montana's customers in 2025; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 1,993 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. Sweet Grass County has data for 2020–2025.
Cite this report
MassOutage (massoutage.com), Sweet Grass County, MT annual power outage report, 2025, 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/2025/montana/sweet-grass-county