August is a good time of year to go. They have sunshine and rain most of the summer and the temperature is fine then too although it is invariably cold near the glaciers. It you want to know more look up weather on the net for any of the towns you would hope to visit and see each for yourself. .... Neil.
Many thanks for your answer. I see you are a regular and obviously seasoned cruiser and appreciate your advice.
Have cruise inside passage to Alaska 3 times, end July to August. It can be warm, cool,wet and reasonably dry, all within a week. The most amazing place. Will go again soon.
Many thanks can't wait.