December weather forecast in Atherton

December in Atherton is the warmest month of the year. In December, the weather in Atherton is typically warm. Average daily high temperature in December is about 25 degrees above zero. On average, Atherton has 18 rainy, 6 partly cloudy, 4 sunny, and 3 cloudy days in December. The rains are usually heavy. December as well as January, February, and March is considered the most uncomfortable time to visit Atherton.