Big Bear Weather In December 2025. The lowest daily average high temperature is 43°f on. 30dayweather long range weather forecasts predict ideal conditions for a storm.

This page contains a list of the average monthly high and low temperatures in big bear lake, california for the month of december each year between 1920 and 2023. Daily high temperatures decrease by 4°f, from 47°f to 43°f, rarely falling below 34°f or exceeding 56°f.