May in Metz is the rainiest month of the year. In May, the weather in Metz is typically warm. Average daily high temperature in May is about 17 degrees above zero. On average, Metz has 18 rainy, 8 sunny, 4 partly cloudy, and 1 cloudy day in May. The rains are usually moderate. May as well as January, February, November, and December is considered the most uncomfortable time to visit Metz.