I'm most concerned about packing. Do I need more long sleave shirts, sweat shirts and windbreakers?? Should I leave shorts home althogher?? How is the temps on board ship this time of year, daytime and night outdoors?
There is nothing more unpredictable than the weather in Alaska. I've been in Ketchikan, according to statistics, the rainiest city in the world. I've been there in total sunshine everytime. No, definitely take your shorts and your bathing suit. The best packing for Alaska is the clothes you can layer. Take a rain poncho, don't bother with umbrellas and some shoes that are resistant to wet weather. Don't forget gloves and some sort of hat. The only time you will be really chilly is when you are in the ice, other than that, Alaska can be anything.
We did an Alaskan cruise in early August. When we were in Juneau and Ketchikan, we were able to walk outside in shorts. We even got into our bathing suits one day to catch some sun. But, after that, it was quite cold. When we were in Glacier Bay, I had five layers of clothes on and still was cold. I would take those sweatshirts, flannel shirts, and sweaters. But, I wouldn't pack too many pairs of shorts or short sleeve shirts.
We just got back and found that the weather varied. In Juneau it reached
72 degrees. Vancouver was around 70. On the open sea it became chilly (wind
chill factor). I thought the Alaskan cruise was very interesting as far as how people dressed. It's the only time I've ever seen people in heavy coats with blue jeans, but wearing Birkenstocks or sandals!
The weather varied so much. But in Hubbard Glacier area it was 46 degrees and extremely chilly. Jeans with a long sleeved shirt and polar fleece didn't seem like enough, so we were all covered up with the wool blankets too.
Ketchican was overcast, but climate felt nice. Maybe 65. It rained a little.
No rain in Skagway but overcast too.
On two days people were actually laying out by the pool and some were even using the pool.
Anything goes!. In Skagway on May 16 we were on deck in swim suits, on May 16 in Ketchikan it was Gore-tex and umbrellas. You'll have to take a bit of everything I'm afraid - but definately take some shorts and rain gear.
The man made fabric called Thinsulate (probably goes by other trade names too) is excellent for Alaska because it is lightweight, waterproof and warm, but doesn't make you swelter if you wear it in mild weather. A jacket or pullover with a hood made out of this stuff is a lifesaver in all the changeable weather. Available in outdoor stores and catalogs.
Beyond that, layering is the trick, as has been said.