Almost all NCL ship's itineraries start and end their cruises in Honolulu or Maui. There are just a few sailings from California and Vancouver when ships reposition from Alaska or drydock.
The weather in Hawaii at sea level doesn't get to cold in the evenings, the coolest temperatures are experienced just before sunrise.
Here's the average temperatures for Honolulu by month: http://www.world66.com/northamerica/...lu/lib/climate
The lowest average monthly low is 16.35C (61.43F) and the highest average monthly high is 28.95C (84.11F).
Do you need a sweater or light jacket for 61F?