Power outage history
Pondera County Montana
7.4hours
without power for the average customer in a typical year, 2018–2025
13th most of 35 in Montana close to the national median
Every day since 2015
Eleven years, one night at a time
Each cell is a day. The brighter it is, the larger the share of Pondera's customers who were without power at that day's worst moment.
Year by year
Hours in the dark, per customer
2020 was the worst well-recorded year, at 14 hours for the average customer. Hatched years have a thin record and are left out of the averages.
Pondera, hours without power per customer
The record
The biggest outages since 2015
Ranked by customer-hours lost: customers out multiplied by how long they stayed out. Times are local.
| Began | Storm | Peak out | Share | Lasted | 90% restored | Customer-hours |
|---|---|---|---|---|---|---|
| Dec 17, 2025 | Windstorm | 2,031 | 100% | 13 h | 8.0 h | 11k |
| Sep 12, 2024 | No storm report | 1,739 | 86% | 5.5 h | 5.5 h | 9.1k |
| Jun 12, 2020 | No storm report | 1,988 | 98% | 8.0 h | 8.0 h | 9.0k |
| Dec 24, 2020 | No storm report | 2,031 | 100% | 3.0 h | 2.8 h | 4.8k |
| Jun 18, 2020 | No storm report | 1,453 | 72% | 2.5 h | 2.5 h | 3.6k |
| Aug 1, 2020 | No storm report | 724 | 36% | 8.2 h | 2.5 h | 3.4k |
| May 19, 2022 | No storm report | 815 | 40% | 6.5 h | 2.0 h | 2.8k |
| Oct 11, 2021 | No storm report | 633 | 31% | 3.8 h | 2.0 h | 2.1k |
| Dec 18, 2025 | Windstorm | 213 | 10% | 16 h | 2.2 h | 1.9k |
| Sep 9, 2021 | No storm report | 531 | 26% | 3.5 h | 3.5 h | 1.9k |
| Nov 5, 2020 | No storm report | 774 | 38% | 9.2 h | 2.5 h | 1.7k |
| Mar 28, 2025 | No storm report | 552 | 27% | 3.0 h | 3.0 h | 1.7k |
| Apr 18, 2023 | Winter storm | 546 | 27% | 3.5 h | 6.2 h | 1.6k |
| Jul 5, 2022 | No storm report | 639 | 31% | 2.5 h | 2.5 h | 1.6k |
| Oct 23, 2021 | No storm report | 659 | 32% | 5.8 h | 2.8 h | 1.5k |
| Mar 9, 2020 | No storm report | 636 | 31% | 2.2 h | 2.2 h | 1.4k |
| Mar 30, 2021 | No storm report | 1,186 | 58% | 2.0 h | 1.0 h | 1.3k |
| Jul 2, 2025 | Thunderstorms | 304 | 15% | 4.8 h | 3.5 h | 1.0k |
| Apr 21, 2020 | No storm report | 297 | 15% | 3.5 h | 14 h | 995 |
| May 7, 2024 | Windstorm | 620 | 31% | 2.0 h | 3.5 h | 974 |
| Jul 18, 2022 | No storm report | 522 | 26% | 1.8 h | 3.2 h | 914 |
| Jun 5, 2025 | No storm report | 653 | 32% | 1.2 h | 1.0 h | 815 |
| Jul 25, 2024 | No storm report | 532 | 26% | 1.2 h | 1.0 h | 665 |
| Nov 23, 2021 | No storm report | 136 | 7% | 4.2 h | 15 h | 578 |
| Dec 23, 2021 | No storm report | 68 | 3% | 8.8 h | – | 522 |
| Oct 4, 2024 | Windstorm | 147 | 7% | 4.2 h | 3.5 h | 499 |
| Jun 20, 2022 | No storm report | 786 | 39% | 2.5 h | 30 min | 486 |
| Feb 8, 2022 | No storm report | 97 | 5% | 5.0 h | – | 485 |
| Feb 1, 2024 | No storm report | 104 | 5% | 4.5 h | 4.5 h | 468 |
| Apr 11, 2022 | No storm report | 104 | 5% | 4.5 h | 4.5 h | 468 |
After the peak
How fast the lights come back
Each line is one major outage, from its peak. The amber line is the typical path.
When it happens
The outage clock
Customer-hours out by month (rings, January innermost) and local hour, 2018–2025.
What was happening
Weather behind the outages
Each outage is matched to NOAA storm reports for Pondera from twelve hours before it began to its peak. Matching shows coincidence, not proof of cause.
- No storm on record 75%
- Windstorm 19%
- Winter storm 3.0%
- Thunderstorms 1.8%
- Wildfire 0.6%
Who keeps the lights on
Utilities serving Pondera
As each utility reports to the Energy Information Administration for its whole Montana territory, not this county alone. Outage minutes include major storm days.
| Utility | Type | Outage min / yr | Excl. major storms | Outages / yr | Residential ¢/kWh | Customers |
|---|---|---|---|---|---|---|
| NorthWestern Energy LLC | Investor Owned | 125 | 117 | 1.10 | 14.4 | 334k |
| Glacier Electric Coop, Inc | MT | – | – | – | 10.2 | 74k |
| Sun River Electric Coop, Inc | MT | 79 | 79 | – | 13.3 | 47k |
| Marias River Electric Coop Inc | MT | – | – | – | 8.8 | 31k |
| WAPA-- Western Area Power Administration | Federal | – | – | – | – | – |
EIA Form 861, latest year each utility reported. Outage minutes are SAIDI, the yearly minutes the average customer goes without power; outages a year are SAIFI.
Next door
Neighbouring counties
About these numbers
Notes
Outages come from the EAGLE-I record of utility outage maps collected every 15 minutes by Oak Ridge National Laboratory. Hours without power are customer-hours divided by the county's 2,031 electricity customers. Averages use well-covered years from 2018. Outages shorter than 15 minutes, and utilities that publish no outage map, are not in the record, so these figures understate the total. How every number is made →