May in Pontarlier is the rainiest and the cloudiest month of the year. In May, the weather in Pontarlier is typically warm. Average daily high temperature in May is about 17 degrees above zero. On average, Pontarlier has 19 rainy, 6 partly cloudy, 4 sunny, and 2 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 Pontarlier.