Averages for Bali in December. Weather lowdown. Although the month of December can be quite cold throughout much of Europe, in Bali, the temperatures are actually warm this time of the year. The average temperature in December is 27°C (81°F), with an average low of 23°C (73°F), and an average high of 30°C (86°F).The beginning of the month sees cloudy days with some sun mixed in, a decent chance of rain, and an average daily temperature of 27°C (81°F), which only drops slightly as the month goes on.lthough the month of December can be quite cold throughout much of Europe, in Bali, the temperatures are actually warm this time of the year.