Sullivan CountyPower Outage History
What this grade means
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 |
|---|---|---|---|
| Jul 19, 2015 | 32 hrs | 19,880 (82%) | Thunderstorm Wind |
| Mar 14, 2023 | 69 hrs | 9,262 (38%) | Winter Storm |
| Dec 17, 2022 | 62 hrs | 8,776 (36%) | Winter Storm |
| Dec 14, 2022 | 2 hrs | 8,672 (36%) | Unnamed event |
| Nov 27, 2018 | 48 hrs | 7,999 (33%) | Heavy Snow |
Was There an Outage on a Specific Date?
Pick a date to see whether a power outage was recorded for Sullivan County, New Hampshire that day.
Over the 12 years from 2014 to 2025, Sullivan County recorded 855 distinct power outage events, averaging 3.3 hours per event.
The single worst outage on record in Sullivan County started July 19, 2015 (Thunderstorm Wind), lasting 32 hours and leaving up to 19,880 customers without power (82% of the county) at its peak.
June has historically been the worst month for outages in Sullivan County, with 87 events recorded during that month across the dataset.
Based on this history, Sullivan County earns a Reliability Grade of F, placing it in the 16th percentile nationally for grid reliability (higher percentile = more reliable).
Similar counties in New Hampshire
Counties with the closest reliability grade and national percentile to Sullivan County.
| County | Grade | National percentile |
|---|---|---|
| Cheshire County | F | 18th |
| Carroll County | F | 11th |
| Belknap County | F | 9th |
| Grafton County | D | 26th |
| Rockingham County | D | 27th |
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 Sullivan County?
Between 2014 and 2025, Sullivan County recorded 855 outage events, averaging 3.3 hours each.
What is Sullivan County's reliability grade?
Sullivan County has a Reliability Grade of F, in the 16th national percentile.
What was the worst power outage in Sullivan County?
The worst outage on record started July 19, 2015 (Thunderstorm Wind), lasting 32 hours and affecting up to 19,880 customers.