September in Basse-Terre is the cloudiest and the warmest month of the year. In September, the weather in Basse-Terre is typically hot. Average daily high temperature in September is about 28 degrees above zero. On average, Basse-Terre has 23 rainy, 4 partly cloudy, 2 sunny, and 1 cloudy day in September. The rains are usually heavy. September as well as January, May, June, and July is considered the most uncomfortable time to visit Basse-Terre.