We will be cruising to Hawaii on Island princess on Sept. 21st of this year. Typically we fly to Hawaii every other year for at least 2 weeks. We love the fall season. Mid-September through October. Prices are lower, much less crowded than summer time and the weather is perfect - a few degrees cooler than mid-summer but very little rain. However, late fall, winter and early spring - there is a chance you will have cooler weather the first day or two cruising out of Southern California and the last couple of days coming back.