September in South Tarawa is the hottest month of the year. In September, the weather in South Tarawa is typically hot. Average daily high temperature in September is about 28 degrees above zero. On average, South Tarawa has 16 rainy, 10 sunny, 3 partly cloudy, and 1 cloudy day in September. The rains are usually heavy. September as well as March, April, May, and June is considered the most uncomfortable time to visit South Tarawa.