January in Big Bear Lake is the rainiest and the cloudiest month of the year. In January, the weather in Big Bear Lake is typically warm. Average daily high temperature in January is about 10 degrees above zero. On average, Big Bear Lake has 14 sunny, 12 partly cloudy, 4 rainy, and 1 cloudy day in January. The rains are usually moderate. January as well as February and December is considered the most uncomfortable time to visit Big Bear Lake.