January weather forecast in Atherton

January in Atherton is the rainiest month of the year. In January, the weather in Atherton is typically hot. Average daily high temperature in January is about 29 degrees above zero. On average, Atherton has 19 rainy, 5 partly cloudy, 4 sunny, and 3 cloudy days in January. The rains are usually heavy. January as well as February, March, and December is considered the most uncomfortable time to visit Atherton.