Missoula County Power Outage History
2020–2025 · Montana
Average — typical outage frequency and duration nationally. How grades are calculated
Outages by year
Outages by month (seasonality)
Worst outage events on record
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| Jul 25, 2024 | 121 hrs | 55,225 (95%) | Excessive Heat |
| Dec 17, 2025 | 124 hrs | 8,400 (14%) | Strong Wind |
| May 9, 2023 | 2 hrs | 7,478 (13%) | Flood |
| Aug 2, 2021 | 2 hrs | 6,378 (11%) | Flash Flood |
| Dec 20, 2023 | 1 hrs | 6,344 (11%) | Dense Fog |
Over the 6 years from 2020 to 2025, Missoula County recorded 273 distinct power outage events, averaging 3.9 hours per event.
The single worst outage on record in Missoula County started July 25, 2024 (Excessive Heat), lasting 121 hours and leaving up to 55,225 customers without power (95% of the county) at its peak.
August has historically been the worst month for outages in Missoula County, with 35 events recorded during that month across the dataset.
Based on this history, Missoula County earns a Reliability Grade of C, placing it in the 42nd percentile nationally for grid reliability (higher percentile = more reliable).
Sized for Missoula County's outage profile
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Similar counties in Montana
Counties with the closest reliability grade and national percentile to Missoula County.
| County | Grade | National percentile |
|---|---|---|
| Teton County | C | 41st |
| Mineral County | D | 39th |
| Meagher County | D | 38th |
| Chouteau County | D | 37th |
| Wheatland County | C | 48th |
FAQ
How often does power go out in Missoula County?
Between 2020 and 2025, Missoula County recorded 273 outage events, averaging 3.9 hours each.
What is Missoula County's reliability grade?
Missoula County has a Reliability Grade of C, in the 42nd national percentile.
What was the worst power outage in Missoula County?
The worst outage on record started July 25, 2024 (Excessive Heat), lasting 121 hours and affecting up to 55,225 customers.