Longest-Lasting Atlantic Storms of 2025

What this chart shows
How long each of the 13 named Atlantic storms of 2025 spent at tropical storm strength or stronger, in days. Time spent as a tropical depression, a remnant low or an extratropical storm is not included.

How the data is collected
HURDAT2 lists each storm's status at the standard synoptic times of 0000, 0600, 1200 and 1800 UTC. Every six-hourly record with tropical storm, hurricane or subtropical storm status was counted as six hours, and the total was divided by 24. Extra records that NHC adds between those times for landfalls and peaks were not counted, so no hour is counted twice.

Background
NHC's report calls Erin a very large and long-lived Cabo Verde hurricane that moved on a long parabolic track around the North Atlantic. The HURDAT2 guide lists the status codes used here: TS for a tropical storm of 34 to 63 knots, HU for a hurricane, and SS for a subtropical storm. The Erin report also records that the system became a tropical storm while making landfall on the island of Santo Antao in the northwestern Cabo Verde Islands by 0600 UTC on 11 August.

Limits
Counting in six-hour steps means a storm's time can be off by up to a few hours at each end. The measure also treats a weak tropical storm and a category 5 hurricane the same, so a long-lived but weak storm can rank above a short, violent one. Storms that became extratropical kept moving and could still be dangerous, but that stage is outside this count.