It would help if you said which ship you are going on and which route. If you are going via New York, it will be cold until 1 or 2 days after New York. If you are going via Canaries, it will only be cold for 2/3days after leaving Southampton.
Spot on, Brian. I think the questioner should also re-read the question as it is a little inexact in its phraseology. regards, Neil.