December in Concepción is the hottest month of the year. In December, the weather in Concepción is typically hot. Average daily high temperature in December is about 33 degrees above zero. On average, Concepción has 11 rainy, 8 partly cloudy, 7 sunny, and 5 cloudy days in December. The rains are usually heavy. December as well as January and February is considered the most uncomfortable time to visit Concepción.