As a female, I don't think I've ever brought jeans w/ me. I usually wear a pair of capris or a long or short fun type of skirt. If you're going in 3 weeks, you should be fine. We've cruised late Mar. and early May, and it's usually fine in the evenings. Yes, bring a light sweater to throw over your shoulders. By the way...I'm one of those "always cold" people, and I do fine on the ship. My DH will bring one pair of jeans to wear on the plane and home, and just so he has them, but it's usually khakis to dinner, then shorts afterwards or he just stays in the khakis. Remember, you're going to be tanned or maybe (hopefully not) burnt, and jeans just might not be the most comfortable thing to wear. I leave the jeans at home, and I'm a jeans kinda gal!!