We've been to Alaska 4 times on cruises and have found that layering is definately the best way to go. The weather in Alaska is incredibly variable! We've been there in July and saw cold and rain, and we've been there in May and saw sun and 70 degree temperatures. We pack for spring/fall weather with a few summer clothes just in case. Bring an umbrella or rain coat if you plan on walking around the towns. You'll love Alaska!