Granite CountyPower Outage History
2020–2025 · Montana
Worse than average — more frequent or longer outages than most counties. This county's recorded history shows more frequent outages and/or longer restoration times than most US counties over the same 12-year period. If you live here, it's worth taking backup power more seriously than an average household would.
Outages by year
Outages by month (seasonality)
Worst outage events on record
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| Nov 5, 2022 | 7 hrs | 1,904 (81%) | Winter Weather |
| May 15, 2020 | 15 hrs | 1,673 (71%) | Heavy Snow |
| May 23, 2024 | 16 hrs | 1,592 (68%) | High Wind |
| Feb 3, 2024 | 4 hrs | 1,446 (62%) | Unnamed event |
| May 3, 2023 | 1 hrs | 1,425 (61%) | Unnamed event |
Over the 6 years from 2020 to 2025, Granite County recorded 252 distinct power outage events, averaging 4.2 hours per event.
The single worst outage on record in Granite County started November 5, 2022 (Winter Weather), lasting 7 hours and leaving up to 1,904 customers without power (81% of the county) at its peak.
August has historically been the worst month for outages in Granite County, with 38 events recorded during that month across the dataset.
Based on this history, Granite County earns a Reliability Grade of D, placing it in the 33rd percentile nationally for grid reliability (higher percentile = more reliable).
Sized for Granite County's outage profile
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Read our mission →Similar counties in Montana
Counties with the closest reliability grade and national percentile to Granite County.
| County | Grade | National percentile |
|---|---|---|
| Flathead County | D | 35th |
| Madison County | D | 31st |
| Chouteau County | D | 37th |
| Meagher County | D | 38th |
| Mineral County | D | 39th |
Most reliable counties in Montana
The top 3 counties in Montana by reliability grade and percentile.
| County | Grade | National percentile |
|---|---|---|
| Powder River County | A | 95th |
| Roosevelt County | A | 94th |
| Fallon County | A | 94th |
Least reliable counties in Montana
The bottom 3 counties in Montana by reliability grade and percentile.
| County | Grade | National percentile |
|---|---|---|
| Lincoln County | F | 14th |
| Sanders County | D | 20th |
| Madison County | D | 31st |
Most reliable counties nationally
The top 3 counties nationally by reliability grade and percentile.
| County | State | Grade | National percentile |
|---|---|---|---|
| Clay County | South Dakota | A | 100th |
| Clearwater County | Minnesota | A | 99th |
| Limestone County | Alabama | A | 99th |
Least reliable counties nationally
The bottom 3 counties nationally by reliability grade and percentile.
| County | State | Grade | National percentile |
|---|---|---|---|
| Clay County | West Virginia | F | 0th |
| Lincoln County | West Virginia | F | 0th |
| Cameron Parish | Louisiana | F | 0th |
FAQ
How often does power go out in Granite County?
Between 2020 and 2025, Granite County recorded 252 outage events, averaging 4.2 hours each.
What is Granite County's reliability grade?
Granite County has a Reliability Grade of D, in the 33rd national percentile.
What was the worst power outage in Granite County?
The worst outage on record started November 5, 2022 (Winter Weather), lasting 7 hours and affecting up to 1,904 customers.