June/July would be the best time as it will have warmed up a little bit by then and you get the longer daylight hours
Alaska cruises run from late May through to September.
Yes the CI writer is correct. Alaska is a wet State, Ketchikan for instance has 13 feet of rain a year, so it's really pot luck as far as good weather goes. We went on the last cruise of the year and had unusually good weather, great whale-watching, saw the glacier calf and it was quite cheap. The glaciers are there all the time so you will see them whenever you go, just don't count on it being sunny, just keep your fingers crossed ....regards Ida Dow.
We returned from Alaska cruise 1st September, we had lovely weather, even Hubbard Glacier was sunny. Ketchigan was the only port of call where we had rain. We were told to wear layers, but mostly a short sleeved t-shirt was ok with sometimes a cardigan/sweater. Lovely cruise- I would highly recommen.