County annual report · FIPS 30039
2022 Granite County, MT Power Outage Report
In 2022, customers in Granite County, MT went without power for an average of 7.7 hours, a total of 18K customer-hours (Montana average 3.5 hours). That ranks 14th worst of 50 Montana counties and 956th of 2,976 nationally.
Compared with MT, the US and 2021
Coverage line is EAGLE-I's share of Montana customers tracked each year.
Biggest outages in Granite County, 2022
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 5, 2022 11:45 | November 5, 2022 20:45 | 9h | 1,904 | 3,603 |
| 2 | July 18, 2022 17:45 | July 19, 2022 03:30 | 9h 45m | 962 | 1,543 |
| 3 | July 2, 2022 23:00 | July 3, 2022 01:30 | 2h 30m | 935 | 2,108 |
| 4 | June 6, 2022 21:45 | June 7, 2022 07:30 | 9h 45m | 934 | 1,952 |
| 5 | May 6, 2022 20:15 | May 6, 2022 22:45 | 2h 30m | 933 | 2,333 |
| 6 | April 20, 2022 15:00 | April 20, 2022 20:00 | 5h | 313 | 891 |
| 7 | November 1, 2022 14:45 | November 1, 2022 23:00 | 8h 15m | 211 | 1,706 |
| 8 | September 7, 2022 22:30 | September 8, 2022 14:45 | 16h 15m | 136 | 461 |
| 9 | March 23, 2022 15:00 | March 23, 2022 22:30 | 7h 30m | 124 | 930 |
| 10 | July 8, 2022 03:00 | July 8, 2022 09:45 | 6h 45m | 40 | 193 |
Outage episodes by size in 2022: 9 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 Granite County reported on EIA Form 861 for 2022, 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) | 2022 | 2.2 hrs | 1.14 | 2.0 hrs | 1.09 |
| Missoula Electric Coop, Inc | 2022 | 4.3 hrs | 1.44 | 4.3 hrs | 1.44 |
| 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 76% of Montana's customers in 2022; 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, 2022, 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/2022/montana/granite-county