In May, the weather in Haderslev is typically warm. Average daily high temperature in May is about 15 degrees above zero. On average, Haderslev has 13 rainy, 9 partly cloudy, 5 sunny, and 4 cloudy days in May. The rains are usually moderate. May as well as January, February, March, and April is considered the most uncomfortable time to visit Haderslev.