May in Dillingen an der Donau is the rainiest month of the year. In May, the weather in Dillingen an der Donau is typically warm. Average daily high temperature in May is about 16 degrees above zero. On average, Dillingen an der Donau has 19 rainy, 8 sunny, and 4 partly cloudy days in May. The rains are usually heavy. May as well as January, February, March, and April is considered the most uncomfortable time to visit Dillingen an der Donau.