Although Hawaii's coastal ocean temperature stays relatively consistent throughout the year, ocean conditions can change drastically depending on the season. Seasons also affect various facing shores in different ways. Some beaches can be calm and gentle during the summer, but rough and dangerous in the winter.
Is Hawaii water warm year-round?
So overall, compared to those warm water areas of the U.S. Gulf and Florida, Hawaiian waters are warmer in the winter and cooler in the summer. As a general rule, Hawaiian waters average 77 degrees in the wintertime to 82 degrees in the summertime.
Is it too cold to swim in Maui in October?
One benefit to visiting Hawaii in the early fall is that the water temperatures are ideal during this month. September and October experience the warmest ocean temperatures in Hawaii, with water temps sitting around 80 degrees F each day.