I have cruised many times on Celebrity, Royal Caribbean, Holland America, Princess Cruises and recently on NCL. All ships are quite chilly in the main dining room, best to bring a wrap or similar whilst you eat. Alright for the males who often wear jackets. The rest of the ship in most cases in quite warm.
Yes it can get cool in certain areas depending on how they have set the air-con and if your sat close to an outlet.You can adjust your cabin Temp, to suite yourself.
The outside deck temp. will be warm and can be very warm and humid and going from one to the other can take a minute to adjust to.
Unfortunately with air conditioning, the warmer the outside temperature, the colder the ship will feel! As already mentioned by BUCKLEY you CAN adjust the temp in your own cabin to your own preference, but you may have to slip on a cardie occasionally whilst strolling around the ship if you do feel the cold a bit (even at home in August) as my dear old Mum used to! Americans in particular seem to like their air con turned down to fridge proportions! Sometimes the heat will hit you like a blast furnace when emerging onto deck at midday! Happy cruising.
Hi, we cruised the Caribbean with Princess & because of the destination, didn't THINK of the air conditioning, therefore, most evenings when dining, we were frozen!! So do take a cardi or light jacket. Walking the deck, you were maybe ok on one side, then maybe chilly if the breeze was round the other side, so as I say, be prepared & enjoy!!