August in Neuilly-sur-Marne is the warmest month of the year. In August, the weather in Neuilly-sur-Marne is typically warm. Average daily high temperature in August is about 24 degrees above zero. On average, Neuilly-sur-Marne has 10 rainy, 10 partly cloudy, 6 sunny, and 5 cloudy days in August. The rains are usually moderate.