In September, the weather in Llandrindod Wells is typically warm. Average daily high temperature in September is about 14 degrees above zero. On average, Llandrindod Wells has 22 rainy, 4 sunny, and 4 cloudy 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 Llandrindod Wells.