County annual report · FIPS 30039
2024 Granite County, MT Power Outage Report
In 2024, customers in Granite County, MT went without power for an average of 24.6 hours, a total of 56K customer-hours (Montana average 8.5 hours). That ranks 4th worst of 51 Montana counties and 404th 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 Granite 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 | May 23, 2024 05:30 | May 24, 2024 00:15 | 18h 45m | 1,592 | 11K |
| 2 | February 3, 2024 02:30 | February 3, 2024 07:00 | 4h 30m | 1,446 | 5,784 |
| 3 | June 19, 2024 07:15 | June 19, 2024 13:15 | 6h | 872 | 4,145 |
| 4 | August 11, 2024 15:00 | August 11, 2024 18:15 | 3h 15m | 596 | 1,937 |
| 5 | February 26, 2024 09:45 | February 26, 2024 20:15 | 10h 30m | 410 | 1,301 |
| 6 | February 20, 2024 12:00 | February 20, 2024 23:15 | 11h 15m | 406 | 2,403 |
| 7 | October 5, 2024 01:00 | October 7, 2024 20:00 | 2d 19h | 313 | 10K |
| 8 | March 1, 2024 13:45 | March 1, 2024 19:30 | 5h 45m | 244 | 541 |
| 9 | August 23, 2024 21:30 | August 24, 2024 15:45 | 18h 15m | 239 | 1,316 |
| 10 | July 25, 2024 00:45 | July 25, 2024 22:15 | 21h 30m | 228 | 3,910 |
Outage episodes by size in 2024: 20 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 Granite 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 |
| Missoula Electric Coop, Inc | 2024 | 26.8 hrs | 3.59 | 8.4 hrs | 2.19 |
| Bonneville Power Administration | - | - | - | - | - |
| NorthWestern Energy | - | - | - | - | - |
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 ÷ 2,293 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. Granite County has data for 2019–2025.
Cite this report
MassOutage (massoutage.com), Granite 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/granite-county