You need a variety of WARM layers. AND a lightweight lined nylon type jacket, key is quick drying. Take sweatshirts, turtlenecks, tshirts. Knit hat, gloves, 2 pair of walking shoes, rain gear. I never take jeans- too bulky, tend to get and stay damp and take forever to dry. For me lined and unline wind pants are perfect. I also always do my laundry off ship in Skagway - can be done in a little over an hour with their fast propane dryers- never mind the great conversations I have gotten in to. You can alway head to the Red Onion for a fast drink and return. Yes bring a tank top and shorts- there can be that much of a range. But most people are underprepared and it will greatly affect your trip.
Layers is the key! I overpacked for Alaska, didn't take a good mix of clothes and ended up buying a couple of short sleeve tees. When you are in town, it can be warmer than you would expect so that's where layers are handy.
It can be as warm as middle sixties and then as you cruise along a glacier or fjord quite cold. Gloves and a hat are not a bad thing to have either.
When I go back, I'll take my jacket with the zip out liner and definitely a hooded sweat shirt.
Thank all of you guys soooo much!!! Your advice really helped me a lot! Now i pretty much know what to pack. LindaE- I noticed that you said that dress in alaska is a lot more casual than on other cruises.....is this also so for the formal dinner nights? I really dont want to over dress or under dress. Thank you!
On formal nights, we saw more people in what I'd call good Sunday clothes than in formal attire. The men did wear suits primarily. Also, a lot of passengers were in jeans or jogging suits in public areas other than the dining room.