massoutage

County annual report · FIPS 30043

2019 Jefferson County, MT Power Outage Report

In 2019, customers in Jefferson County, MT went without power for an average of 0.0 hours, a total of 4 customer-hours (Montana average 0.6 hours). That ranks 33rd worst of 38 Montana counties and 2927th of 2,945 nationally.

Summary data CSVJSON
Avg hrs / customer
0.0
5,322 customers
Customer-hours out
4
Peak customers out
1
Outages ≥1,000 out
0
0 of 10,000+ · 1 total
Longest outage
3h 30m
began December 30, 2019
Rank in state
33rd/38
2927th of 2,945 US

Compared with MT, the US

Jefferson County, MT average hours without power per customer compared with state and national averages, 2019Jefferson County 0.0 hours, Montana average 0.6 hours, US average 4.7 hoursJefferson CountyJefferson County0.0hMontana averageMontana average0.6hUS averageUS average4.7h
Use the arrow keys to read values.
Average hours without power per customer in 2019.

Month by month

CSVJSON
Jefferson County, MT customer-hours without power by month, 2019Jan 0, Feb 0, Mar 0, Apr 0, May 0, Jun 0, Jul 0, Aug 0, Sep 0, Oct 0, Nov 0, Dec 4012340Jan0Feb0Mar0Apr0May0Jun0Jul0Aug0Sep0Oct0Nov4Dec
Use the arrow keys to read values.
Customer-hours; December was the worst month.

Jefferson County year over year

CSVJSON
Jefferson County, MT: average hours without power per customer by year2015: no data; 2016: no data; 2017: no data; 2018: no data; 2019: 0.0h, coverage 75%; 2020: 3.6h, coverage 76%; 2021: 4.8h, coverage 76%; 2022: 3.4h, coverage 76%; 2023: 1.6h; 2024: 8.8h; 2025: 20.9h01020300%50%100%n/a2015n/a2016n/a2017n/a20180.0h20193.6h20204.8h20213.4h20221.6h20238.8h202420.9h2025
Use the arrow keys to read values.
Average hours without power per customer. Line: EAGLE-I coverage, share of customers tracked (right axis).

Coverage line is EAGLE-I's share of Montana customers tracked each year.

Biggest outages in Jefferson County, 2019

The 1 outage episodes with the most customers out at once. Times are UTC.

CSVJSON
#Started (UTC)Ended (UTC)DurationPeak outCustomer-hours
1December 30, 2019 18:45December 30, 2019 22:153h 30m14

Outage episodes by size in 2019: 0 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 2019, or their most recent earlier filing. Utility-wide figures, not county-specific.

CSVJSON
UtilityEIA yearSAIDISAIFISAIDI excl. major eventsSAIFI excl. major events
NorthWestern Energy LLC - (MT)20181.7 hrs1.081.7 hrs1.08
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 75% of Montana's customers in 2019; 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, 2019, 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/2019/montana/jefferson-county

summary CSVJSONyears CSVJSONmonths CSVJSONevents CSVJSONutilities CSVJSON