In September, the weather in Bad Neuenahr-Ahrweiler is typically warm. Average daily high temperature in September is about 18 degrees above zero. On average, Bad Neuenahr-Ahrweiler has 13 partly cloudy, 11 sunny, and 6 rainy days in September. The rains are usually light. September as well as August is considered the most comfortable time to visit Bad Neuenahr-Ahrweiler.