January in Kailua-Kona is the sunniest month of the year. In January, the weather in Kailua-Kona is typically warm. Average daily high temperature in January is about 22 degrees above zero. On average, Kailua-Kona has 15 sunny, 14 partly cloudy, 1 rainy, and 1 cloudy day in January. The rains are usually light. January as well as February, March, and December is considered the most comfortable time to visit Kailua-Kona.