In December, the weather in Kailua-Kona is typically warm. Average daily high temperature in December is about 23 degrees above zero. On average, Kailua-Kona has 17 partly cloudy, 11 sunny, 2 rainy, and 1 cloudy day in December. The rains are usually light. December as well as January, February, and March is considered the most comfortable time to visit Kailua-Kona.