Well it's not going to be completely rained out but nor is it clear skies. The forecast calls for scattered clouds while you're on your trip. There's a chance for rain but the temperatures appear to be in the 70s-80s. Not sure where you're from but that's no reason to pack a jacket. I'd say pack light but bring a light jacket in case of rain. Also, being on the cruise ship tends to be a bit cooler then on land. Bring your swimsuit just in case! Just because it's not sunny doesn't mean you can't enjoy the beach or the pool.
As far as clothes are concerned for land...Like I said if 70-80s is comfortable weather for you maybe bring half shorts half pants. If that's cold for you, pack pants. Ha, you can compromise and bring capris! Also, plan for any tours or excursions you go on. If it requires a bit of walking or hiking make sure you'll be comfortable in your attire.
If you'd like to see the up-to-date weather while you're on your trip, check this
site out. Also, some cruise ships have a channel on the room tvs that will give you up-to-date information so be sure to look into that.
Have a fun trip!