In May, the weather in La Grande-Motte is typically warm. Average daily high temperature in May is about 22 degrees above zero. On average, La Grande-Motte has 13 sunny, 8 rainy, 7 partly cloudy, and 3 cloudy days in May. The rains are usually moderate. May as well as June, July, and September is considered the most comfortable time to visit La Grande-Motte.