Spent Christmas Eve at Aulani and did the Aunties Breakfast Buffet on Christmas day. The resort did not feel as crowded as it did in July when I spent a night there. There was a lot of really good decorating for the resort and rather than santa Mickey, Mickey was in his aloha holiday finest. I really liked this because I have seen Santa Mickey more times that I can count. The breakfast buffet was really good because they had the Hawaiian Christmas songs and activities for keiki(kids). Christmas Eve we got appetizers at Off the Hook and were more than filled. Overall a great way to spend the holiday.
Now as for your questions about the weather, this is winter in Hawaii which means Monsoon season. Christmas Eve cleared up ok, Christmas Day was typical for Hawaii. Rainy, overcast, kinda cool. Now I can say that next year will more than likely be the same because I have lived in Hawaii for four years and this is the time of year I loose my tan. Because the sun can and does hide super well.