Jefferson CountyPower Outage History
What this grade means
(How grades are calculated)Bottom 20% least reliable nationally — frequent and/or long outages. This county ranks in the least reliable fifth of all US counties in our dataset: some combination of frequent outages, long restoration times, or customers affected puts it near the bottom nationally. Backup power is worth prioritizing here rather than treating it as optional.
Outages by year
Outages by month (seasonality)
Worst outage events on record
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| Oct 10, 2020 | 230 hrs | 4,396 (90%) | Hurricane Delta |
| Feb 17, 2021 | 19 hrs | 4,393 (90%) | Winter Storm Uri |
| Feb 18, 2021 | 89 hrs | 3,763 (77%) | Winter Storm Uri |
| Jun 27, 2023 | 47 hrs | 2,919 (60%) | Unnamed event |
| Mar 23, 2020 | <1 hr | 2,665 (55%) | Unnamed event |
Was There an Outage on a Specific Date?
Pick a date to see whether a power outage was recorded for Jefferson County, Mississippi that day.
Over the 11 years from 2015 to 2025, Jefferson County recorded 1,239 distinct power outage events, averaging 5.7 hours per event.
The single worst outage on record in Jefferson County started October 10, 2020 (Hurricane Delta), lasting 230 hours and leaving up to 4,396 customers without power (90% of the county) at its peak.
July has historically been the worst month for outages in Jefferson County, with 162 events recorded during that month across the dataset.
Based on this history, Jefferson County earns a Reliability Grade of F, placing it in the 1st percentile nationally for grid reliability (higher percentile = more reliable).
Similar counties in Mississippi
Counties with the closest reliability grade and national percentile to Jefferson County.
| County | Grade | National percentile |
|---|---|---|
| Claiborne County | F | 0th |
| Wilkinson County | F | 0th |
| Amite County | F | 2nd |
| Franklin County | F | 2nd |
| Copiah County | F | 4th |
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 2015 and 2025, Jefferson County recorded 1,239 outage events, averaging 5.7 hours each.
What is Jefferson County's reliability grade?
Jefferson County has a Reliability Grade of F, in the 1st national percentile.
What was the worst power outage in Jefferson County?
The worst outage on record started October 10, 2020 (Hurricane Delta), lasting 230 hours and affecting up to 4,396 customers.