Clothes to pack for Homelands Cruise in early August

Starting to think about packing...any suggestions? I realize it has to do with weather and of course, "layering" is always a good idea, but any other helpful hints would be appreciated.

Hard to say but luckily Viking provides free laundry and soap..

We were on the May homelands cruise on the Viking Sky , we brought clothes thinking it would be 50s and rainy..but it was lower 70s and sunny..

Friends went in June and they wore Jackets..so one never knows..layers..and enjoy. BEST CRUISE EVER!

We leave Friday for the same tour. I've packed and repacked since the weather seems to be quite warm now. Even Bergen is in the 70*s, but I have layers in case it changes! I'm hoping it won't be too hot in St. Petersburg. With no air con, I've read the museums can be uncomfortable when they are packed with tourists.