You answered your own question when you said you knew it could vary greatly. We've seen very cool spells, with rain in may/june, and one of the prettiest, warmest cruises we took was in early June. If you want to be assured of warm, sunny weather, go somewhere else. If you are willing to accept what Mother Nature is dishing out, to get a chance to see some of the most magnificent scenery God has created, go to Alaska ( and take jackets, sweaters, and raingear).