September in Porto Moniz is the warmest month of the year. In September, the weather in Porto Moniz is typically warm. Average daily high temperature in September is about 23 degrees above zero. On average, Porto Moniz has 21 sunny, 7 partly cloudy, 1 rainy, and 1 cloudy day in September. The rains are usually light. September as well as July and August is considered the most comfortable time to visit Porto Moniz.