In September, the weather in Le Grau-Du-Roi is typically warm. Average daily high temperature in September is about 23 degrees above zero. On average, Le Grau-Du-Roi has 22 sunny, 7 partly cloudy, and 1 rainy day in September. The rains are usually light. September as well as June, July, and August is considered the most comfortable time to visit Le Grau-Du-Roi.