I think you've lucked out. I've done an Alaskan cruise twice - once in early July and once in mid August. August was by far the best as far as wildlife was concerned. We saw one set of 4 dolphins that swam alongside the ship for a while, a lot of whales -- mainly we just saw their spouting and the odd tail. The salmon will be so thick in Ketchikan that you'll think you could walk across the river on their backs. In Juneau we saw a mother bear feeding her twin cubs salmon, right off the path at the Mendenhall Glacier. There's still lots of daylight -- although I can't be specific about the hours.
The weather was similar both times I think. Sometimes shirtsleeve weather and other times light jackets and the odd bit of rain.