May in Clifden is the sunniest month of the year. In May, the weather in Clifden is typically warm. Average daily high temperature in May is about 12 degrees above zero. On average, Clifden has 18 rainy, 6 sunny, 4 cloudy, and 3 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 Clifden.