January in Bad Mergentheim is the snowiest and the coldest month of the year. In January, the weather in Bad Mergentheim is typically cold. Average daily high temperature in January is about 3 degrees above zero. On average, Bad Mergentheim has 9 rainy, 9 partly cloudy, 8 cloudy, 4 sunny, and 1 snowy day in January. The rains are usually moderate. January as well as February, March, October, and November is considered the most uncomfortable time to visit Bad Mergentheim.