January in Aberystwyth is the rainiest and the coldest month of the year. In January, the weather in Aberystwyth is typically cold. Average daily high temperature in January is about 6 degrees above zero. On average, Aberystwyth has 24 rainy, 5 sunny, 1 cloudy, and 1 partly cloudy day in January. The rains are usually heavy. January as well as February, May, July, and August is considered the most uncomfortable time to visit Aberystwyth.