We were on the June 14th cruise. I am a person who is always cold! I found the inside of the ship warm. I wore a light jacket inside and never needed anything heavier than that (even at night and in the theatres). Wore my sandals indoors. Had to dress a little warmer for on deck--polar fleece on the Tracy Arm day. There were also blankets available on deck. We even slept with the veranda opened a bit for some cool air (I know, I know--you're not suppose to!).
Wore layers on excursions--not too cold just a little drizzly. Didn't pack a heavy jacket and I'm glad I didn't! Didn't need the gloves or hats that I packed either!
That being said, I am glad that I had my heavy clothes 'just in case!' I would rather be warm than not.