September in Manacapuru is the hottest month of the year. In September, the weather in Manacapuru is typically hot. Average daily high temperature in September is about 32 degrees above zero. On average, Manacapuru has 21 rainy, 5 partly cloudy, 2 sunny, and 2 cloudy days in September. The rains are usually heavy. September as well as January, February, March, and April is considered the most uncomfortable time to visit Manacapuru.