December in Dien Bien Phu is the coldest month of the year. In December, the weather in Dien Bien Phu is typically warm. Average daily high temperature in December is about 19 degrees above zero. On average, Dien Bien Phu has 17 cloudy, 7 partly cloudy, 5 sunny, and 2 rainy days in December. The rains are usually light.