County annual report · FIPS 30013
2020 Cascade County, MT Power Outage Report
In 2020, customers in Cascade County, MT went without power for an average of 8.3 hours, a total of 323K customer-hours (Montana average 5.6 hours). That ranks 15th worst of 50 Montana counties and 927th of 3,019 nationally.
Compared with MT, the US and 2019
Coverage line is EAGLE-I's share of Montana customers tracked each year.
Biggest outages in Cascade County, 2020
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 8, 2020 02:30 | November 11, 2020 17:30 | 3d 15h | 5,616 | 85K |
| 2 | February 1, 2020 11:00 | February 3, 2020 21:00 | 2d 10h | 5,244 | 48K |
| 3 | March 19, 2020 13:45 | March 20, 2020 22:00 | 1d 8h | 3,832 | 6,913 |
| 4 | June 24, 2020 14:30 | June 26, 2020 02:15 | 1d 11h | 3,634 | 11K |
| 5 | March 17, 2020 16:00 | March 18, 2020 08:30 | 16h 30m | 2,946 | 15K |
| 6 | September 7, 2020 11:00 | September 8, 2020 01:15 | 14h 15m | 2,433 | 12K |
| 7 | March 24, 2020 14:15 | March 25, 2020 00:30 | 10h 15m | 2,160 | 2,994 |
| 8 | October 30, 2020 18:45 | October 31, 2020 04:00 | 9h 15m | 2,002 | 12K |
| 9 | June 26, 2020 03:45 | June 30, 2020 06:00 | 4d 2h | 1,961 | 4,152 |
| 10 | February 25, 2020 17:15 | February 26, 2020 00:30 | 7h 15m | 1,734 | 5,154 |
Outage episodes by size in 2020: 77 reached 100+ customers, 21 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 Cascade County reported on EIA Form 861 for 2020, 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) | 2020 | 2.8 hrs | 1.13 | 2.0 hrs | 1.02 |
| WAPA-- Western Area Power Administration | - | - | - | - | - |
| NorthWestern Energy | - | - | - | - | - |
| Fergus Electric Coop, Inc | - | - | - | - | - |
| Sun 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 2020; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 39,166 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. Cascade County has data for 2019–2025.
Cite this report
MassOutage (massoutage.com), Cascade County, MT annual power outage report, 2020, 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/2020/montana/cascade-county