September in Valencia is the hottest month of the year. In September, the weather in Valencia is typically hot. Average daily high temperature in September is about 28 degrees above zero. On average, Valencia has 25 rainy, 3 cloudy, 1 sunny, and 1 partly cloudy day in September. The rains are usually heavy. September as well as January, March, April, and May is considered the most uncomfortable time to visit Valencia.