Did the Alaska cruise 2 yrs ago in Sep for 7 days. We sailedon Vision of the Seas. It was fabulous trip. Temperature was around 50 to 55F, poolwas heated,hot tubs. We had the pool ourselves.The water was great,a little chilly getting out but not unbearable. If you can try and get a balcony. The sea was rough only one day, and we didnt notice any difference on board. There was some rain and wind in ports.Bring a warm waterproof jacket. Dont let the weather deter from taking this trip. It is worth it no matter what. Have a good one