Isaias has strengthened into the first hurricane of the 2026 Atlantic season, setting a record for the latest date on which the basin's first hurricane has formed, CNN reported.

The previous record was shared by Hurricane Gustav in 2002 and Hurricane Humberto in 2013, both of which formed on September 11.

Isaias's maximum sustained winds have climbed to 105 mph (about 169 km/h). The National Hurricane Center expects the storm to briefly become a major hurricane early Friday morning. A major hurricane is defined as a storm of Category 3 strength or higher, with winds of at least 111 mph.

Record-warm waters in the Gulf for this time of year are helping to fuel the storm. However, less favourable atmospheric conditions near the coast are forecast to weaken Isaias slightly before it makes landfall late Friday or early Saturday. Even so, it is still expected to come ashore as a strong Category 2 hurricane with winds of 110 mph.

Isaias is the first hurricane to form in the Atlantic basin in nearly a year. The last was Hurricane Melissa, which formed on October 25, 2025.