September in Wicklow is the cloudiest month of the year. In September, the weather in Wicklow is typically warm. Average daily high temperature in September is about 14 degrees above zero. On average, Wicklow has 15 rainy, 13 cloudy, and 2 sunny days in September. The rains are usually moderate. September as well as January, February, March, and April is considered the most uncomfortable time to visit Wicklow.