County annual report · FIPS 30073
2021 Pondera County, MT Power Outage Report
In 2021, customers in Pondera County, MT went without power for an average of 5.8 hours, a total of 12K customer-hours (Montana average 5.0 hours). That ranks 24th worst of 51 Montana counties and 1187th of 2,974 nationally.
Compared with MT, the US and 2020
Coverage line is EAGLE-I's share of Montana customers tracked each year.
Biggest outages in Pondera County, 2021
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | March 31, 2021 02:30 | March 31, 2021 04:30 | 2h | 1,186 | 1,294 |
| 2 | October 23, 2021 14:00 | October 23, 2021 19:45 | 5h 45m | 659 | 1,535 |
| 3 | October 12, 2021 02:00 | October 12, 2021 05:45 | 3h 45m | 633 | 2,119 |
| 4 | September 9, 2021 17:30 | September 9, 2021 21:00 | 3h 30m | 531 | 1,859 |
| 5 | May 22, 2021 16:45 | May 22, 2021 21:15 | 4h 30m | 137 | 465 |
| 6 | November 24, 2021 00:00 | November 24, 2021 04:30 | 4h 30m | 136 | 578 |
| 7 | November 2, 2021 16:15 | November 2, 2021 21:15 | 5h | 108 | 372 |
| 8 | January 3, 2021 20:15 | January 3, 2021 23:15 | 3h | 97 | 291 |
| 9 | May 16, 2021 02:00 | May 16, 2021 05:45 | 3h 45m | 97 | 364 |
| 10 | May 20, 2021 15:15 | May 21, 2021 01:45 | 10h 30m | 97 | 231 |
Outage episodes by size in 2021: 7 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 Pondera County reported on EIA Form 861 for 2021, 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) | 2021 | 2.5 hrs | 1.37 | 2.1 hrs | 1.18 |
| WAPA-- Western Area Power Administration | - | - | - | - | - |
| Sun River Electric Coop, Inc | - | - | - | - | - |
| Glacier Electric Coop, Inc | - | - | - | - | - |
| Marias River 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 76% of Montana's customers in 2021; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 2,031 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. Pondera County has data for 2019–2025.
Cite this report
MassOutage (massoutage.com), Pondera County, MT annual power outage report, 2021, 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/2021/montana/pondera-county