DW and I are planning on going to Alaska in June, RT from Seattle and being our first cruise there, we were wondering how to dress. We plan on doing some excursions, probably not the most rugged ones, but perhaps some semi-rugged ones, and probably at least one dealing with a boat of some sort (canoing, kayaking, not sure yet). The last thing I want to do is overpack!! Do we need shorts or will we never wear them? We are leaning toward the NCL Pearl, so they really don't require "formal" so I'm not sure whether to bring a jacket/blazer/suit or not. Any help would be great. Thanks.
Daytime temperatures in Ketchikan and Juneau tend to be in the 60's, but daytime temperatures in Vancouver and Skagway and Anchorage tend to be around 80. Thus, you probably will want a couple pairs of shorts, but not as many as you might take on a Caribbean cruise. Also, one swimsuit will be enough. Slacks (dockers, etc.) are fine for most shore excursions in the cooler areas. Rain is very likely in Ketchikan and moderately likely in Juneau, as these cities are in the midst of a gorgeous temperate rain forest, so bring a nylon windbreaker and a suitable hat that will keep you dry in addition to a couple sweaters or sweatshirts to wear in these ports.
You obviously should bring clothing that's appropriate for any unusual shore excursions (wilderness hiking, ziplining, or dog mushing on a glacier, for example) that you intend to take, unless the tour's description states that the operator will provide it, as well as clothing appropriate for any activities of a similar nature that you intend to pursue on your own.
Most cruises to Alaska visit one glacier area or another, and the bays with glaciers are chronically full of ice water -- at 32 degrees -- due to the calving action of the glaciers. The air over these bays is not much warmer -- typically in the upper 30's. Also, the best viewing of glaciers is invariably out on deck -- where you will want a warm jacket, hat, and gloves in these areas.
Finally, you might as well bring at least one set of dress clothing in case you find that you need it for some of the activities aboard ship. I'm not really sure how Norwegian's "formal optional" works, but my impression is that some of the restaurants and events do require dress clothes, while others do not, on those evenings.
Have a great cruise!