Atlantic hurricane season runs June 1 through November 30 and covers every Caribbean and Bahamas itinerary, plus the Florida and Gulf Coast homeports most of them sail from. Storm activity is not evenly spread across those six months. The peak window is mid-August through mid-October, while early June and late November carry much lower risk.
Cruise lines track storms closely and routinely reroute itineraries days in advance, swapping an at-risk port for a calmer one rather than sailing through a system. Outright cancellations are uncommon and usually limited to storms tracking directly toward a ship's homeport.
The southern Caribbean, including Aruba, Bonaire, Curacao, and Barbados, sits largely outside the main hurricane belt and stays a safer year-round option even at the peak of the season. Travel insurance with a "cancel for any reason" or hurricane-specific rider is worth the cost for any sailing booked June through October.