Nassau County Power Outage History
2014–2025 · Florida
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 |
|---|---|---|---|
| Sep 11, 2017 | 216 hrs | 48,802 (65%) | Hurricane Irma |
| Sep 27, 2024 | 66 hrs | 31,083 (41%) | Hurricane Helene |
| Oct 7, 2016 | 24 hrs | 18,519 (24%) | Hurricane Matthew |
| Mar 21, 2018 | 1 hrs | 16,334 (22%) | Hail |
| Aug 23, 2015 | 2 hrs | 16,192 (21%) | Thunderstorm Wind |
Over the 12 years from 2014 to 2025, Nassau County recorded 729 distinct power outage events, averaging 2.0 hours per event.
The single worst outage on record in Nassau County started September 11, 2017 (Hurricane Irma), lasting 216 hours and leaving up to 48,802 customers without power (65% of the county) at its peak.
July has historically been the worst month for outages in Nassau County, with 101 events recorded during that month across the dataset.
Based on this history, Nassau County earns a Reliability Grade of C, placing it in the 40th percentile nationally for grid reliability (higher percentile = more reliable).
Sized for Nassau County's outage profile
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Similar counties in Florida
Counties with the closest reliability grade and national percentile to Nassau County.
| County | Grade | National percentile |
|---|---|---|
| St. Lucie County | D | 40th |
| Hernando County | D | 40th |
| Broward County | C | 41st |
| Santa Rosa County | C | 42nd |
| Martin County | D | 37th |
FAQ
How often does power go out in Nassau County?
Between 2014 and 2025, Nassau County recorded 729 outage events, averaging 2.0 hours each.
What is Nassau County's reliability grade?
Nassau County has a Reliability Grade of C, in the 40th national percentile.
What was the worst power outage in Nassau County?
The worst outage on record started September 11, 2017 (Hurricane Irma), lasting 216 hours and affecting up to 48,802 customers.