January in Saint-Germain-en-Laye is the coldest month of the year. In January, the weather in Saint-Germain-en-Laye is typically cold. Average daily high temperature in January is about 5 degrees above zero. On average, Saint-Germain-en-Laye has 13 rainy, 9 cloudy, 5 partly cloudy, and 4 sunny days in January. The rains are usually light. January as well as February, March, May, and November is considered the most uncomfortable time to visit Saint-Germain-en-Laye.