Weather in Hawaii is very consistent, with only minor changes in temperature throughout the year. There are really only 2 seasons in Hawaii: summer (called Kau in Hawaiian) from May to October and winter (Ho’oilo) from November to April. The average daytime summer temperature at sea level is 85º F. (29.4 C) while the average daytime winter temperature is 78º (25.6º C). Temperatures at night are approximately 10º F. lower.