We cruised Hawaii to Ensanada in April. Hawaii was beautiful. I planned to lay by the pool everyday and read a good book on our 7 day cruise back to the mainland. Boy was I wrong!
As we left Kauai a BBQ was served on the Lido deck. What a great way to say goodby to Hawaii. Wrong! Not 5 miles out to sea and the winds picked up so bad that food was flying off the plates. Within 20 minutes everyone was inside. For 90% of the cruise we stayed inside. It was only about 65 degrees out and the wind chill factor was colder than that. Too cold to use the pool or even lay out. You could hardly walk. Good thing the Hawaiian Ambassador had so many great things planned inside.
I can only assume December will be colder. I would plan accordingly.