August in Kihei is the sunniest month of the year. In August, the weather in Kihei is typically warm. Average daily high temperature in August is about 25 degrees above zero. On average, Kihei has 22 sunny, 7 partly cloudy, 1 rainy, and 1 cloudy day in August. The rains are usually light. August as well as January, March, April, and May is considered the most comfortable time to visit Kihei.