January in Passau is the snowiest, the cloudiest, and the coldest month of the year. In January, the weather in Passau is typically freezing. Average daily high temperature in January is about zero. On average, Passau has 11 snowy, 9 cloudy, 7 rainy, and 4 sunny days in January. The snowfalls are usually moderate. January as well as February, March, April, and November is considered the most uncomfortable time to visit Passau.