From what I've heard from others that have cruised Alaska, you will need to dress in layers and be sure to bring some rain gear. The weather is not real predictable, so be prepared for anything, with any luck you'll have some super nice days. Enjoy the scenery, I hear its breathtaking!
Donna is right you have to dress in layers. You can have nice weather to rainy cold weather. Last time we went we were on the Totem Bite tour and it was warm and sunny and all of a sudden a fog bank roled in and the temperature dropped a good 15 degrees. One half hour later the fog was gone and it was warm again.
For daytime ashore, take clothes you can layer, such as cotton sweater/sweat shirt. It may be warm or cool. I find a waterproof poncho with hood and lots of pockets indispensible. Of course, very comfortable walking shoes, binoculars, camera (extra film).
For formal nights, I take separates I can layer ... dress things up with scarves and jewelry. One black silk suit, with pants and long skirt, mixed with assored tops and jewelry could take me around the world!
> This will be our first cruise. What do we need to pack for
> an Alaskan cruise in May? Any ideas would be appreciated.
This is the only bad thing about an Alaska cruise. U need to pack for all 4 season, because you could see them all <G>
They're well worth the trouble though!