Whether it is "cold" depends entirely on your itinerary, but generally, October is a shoulder month with unpredictable conditions. In the Caribbean, it remains very warm (high 80s), though it is the tail end of hurricane season, so you may face rain and high humidity. In the Mediterranean, October is mild and pleasant for sightseeing (low 60s to mid 70s), but it can feel quite chilly on the open deck at night due to the "wind chill" created by the ship’s movement. If you are cruising in Northern Europe or Canada/New England, it will definitely be cold, with temperatures often dipping into the 40s or 50s. Regardless of the destination, cruise ships are always kept heavily air-conditioned indoors, so it is a 2026 travel "must" to pack a light jacket or pashmina for the dining rooms and theaters, which can feel quite frosty compared to the tropical air outside.