Jefferson CountyPower Outage History
2020–2025 · Montana
Better than average — fewer or shorter outages than most counties.
Outages by year
Outages by month (seasonality)
Worst outage events on record
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| May 14, 2024 | 6 hrs | 2,681 (49%) | Heavy Snow |
| Mar 9, 2021 | 1 hrs | 1,694 (31%) | Unnamed event |
| Nov 13, 2024 | 4 hrs | 1,484 (27%) | Wildfire |
| Aug 28, 2024 | 1 hrs | 1,479 (27%) | Wildfire |
| Aug 24, 2022 | 3 hrs | 1,442 (26%) | Unnamed event |
Over the 6 years from 2020 to 2025, Jefferson County recorded 247 distinct power outage events, averaging 3.2 hours per event.
The single worst outage on record in Jefferson County started May 14, 2024 (Heavy Snow), lasting 6 hours and leaving up to 2,681 customers without power (49% of the county) at its peak.
August has historically been the worst month for outages in Jefferson County, with 34 events recorded during that month across the dataset.
Based on this history, Jefferson County earns a Reliability Grade of B, placing it in the 77th percentile nationally for grid reliability (higher percentile = more reliable).
Sized for Jefferson County's outage profile
See more picks in our Best Small Power Stations (Under 1,000Wh) roundup.
Outage-prep kit
See our outage-prep guides.
Similar counties in Montana
Counties with the closest reliability grade and national percentile to Jefferson County.
| County | Grade | National percentile |
|---|---|---|
| Rosebud County | B | 78th |
| Pondera County | B | 76th |
| Sheridan County | B | 75th |
| Lake County | A | 80th |
| Daniels County | A | 81st |
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 Jefferson County?
Between 2020 and 2025, Jefferson County recorded 247 outage events, averaging 3.2 hours each.
What is Jefferson County's reliability grade?
Jefferson County has a Reliability Grade of B, in the 77th national percentile.
What was the worst power outage in Jefferson County?
The worst outage on record started May 14, 2024 (Heavy Snow), lasting 6 hours and affecting up to 2,681 customers.