In December, the weather in Aix-en-Provence is typically warm. Average daily high temperature in December is about 10 degrees above zero. On average, Aix-en-Provence has 14 sunny, 8 rainy, 5 partly cloudy, and 4 cloudy days in December. The rains are usually moderate. December as well as January, February, and November is considered the most uncomfortable time to visit Aix-en-Provence.