At that time of year it won't be 'scorching'. It can get hot, but not unbearable. Plus, all the ports are on the water, so there is usually a constant breeze.
I'm very fair skinned and can get sunburned rather easily. One of the things I found that works very well for me to help keep from getting sunburned while being comfortable so I don't get overly hot, are those shirts made from very lightweight material, similar to the Columbia Bahama nylon shirt. (If you ever watch Survivor, Jeff Probst is always wearing these on the show.) I have two long sleeve and one short sleeve that I always travel with and they are wonderful. They dry fast, very lightweight, take up very little space, and are excellent in hot weather. My wife has a couple of short sleeve ones and she loves them because they are extremely comfortable.