Roughly speaking, there are two seasons: from November through April the climate is cooler and more humid, with daily high temperatures of about 81?F and lows of 65?F at night. More rain falls during the cooler season, but there are also many lovely sunny days. From June through October the climate is warmer and drier with daily high temperatures of about 84?F and lows of 70?F at night. Most people divide the year into two climate periods - the Dry Season and the Humid Season.
http://www.discounthawaii4u.com/hawaii-climate.htm