County annual report · FIPS 30043
2023 Jefferson County, MT Power Outage Report
In 2023, customers in Jefferson County, MT went without power for an average of 1.6 hours, a total of 8,534 customer-hours (Montana average 1.8 hours). That ranks 30th worst of 50 Montana counties and 2446th of 2,977 nationally.
Compared with MT, the US and 2022
Coverage line is EAGLE-I's share of Montana customers tracked each year.
Biggest outages in Jefferson County, 2023
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | April 13, 2023 05:45 | April 14, 2023 01:45 | 20h | 263 | 1,019 |
| 2 | May 9, 2023 23:00 | May 10, 2023 03:45 | 4h 45m | 243 | 381 |
| 3 | November 7, 2023 15:15 | November 7, 2023 22:30 | 7h 15m | 219 | 1,099 |
| 4 | May 3, 2023 14:45 | May 3, 2023 23:00 | 8h 15m | 139 | 296 |
| 5 | June 8, 2023 15:45 | June 8, 2023 20:45 | 5h | 111 | 349 |
| 6 | October 18, 2023 17:15 | October 18, 2023 20:45 | 3h 30m | 104 | 312 |
| 7 | August 29, 2023 23:00 | August 30, 2023 09:15 | 10h 15m | 88 | 476 |
| 8 | May 6, 2023 18:00 | May 6, 2023 22:00 | 4h | 85 | 68 |
| 9 | January 29, 2023 15:30 | January 29, 2023 19:30 | 4h | 65 | 104 |
| 10 | February 27, 2023 21:30 | February 28, 2023 01:00 | 3h 30m | 64 | 209 |
Outage episodes by size in 2023: 6 reached 100+ customers, 0 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 Jefferson County reported on EIA Form 861 for 2023, 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) | 2023 | 1.7 hrs | 0.93 | 1.7 hrs | 0.93 |
| Bonneville Power Administration | - | - | - | - | - |
| NorthWestern Energy | - | - | - | - | - |
| Vigilante 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 2023; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 5,322 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. Jefferson County has data for 2019–2025.
Cite this report
MassOutage (massoutage.com), Jefferson County, MT annual power outage report, 2023, 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/2023/montana/jefferson-county