Temperatures throughout the Caribbean are fairly constant year-round, but nighttime temperatures can drop to as low as 65°F during the winter, while daytime highs might go up to 95°F in the summer. But ships cruise the Caribbean year-round. In the Caribbean, the low season runs from approximately mid-September through mid-April. The most expensive and months are usually the summer months and holiday periods, and the best bargains are sometimes found in the fall, in the latter half of the storm season. Hurricane season runs a full six months of the year in the Caribbean -- from June 1 through November 30. Although cruise ships stay well out of the way of these storms, hurricanes and tropical storms -- their less-powerful relatives -- can affect the weather throughout the Caribbean for days, and damage to ports can force last-minute itinerary changes.