May in Bontang is the rainiest month of the year. In May, the weather in Bontang is typically hot. Average daily high temperature in May is about 31 degrees above zero. On average, Bontang has 29 rainy, 1 sunny, and 1 cloudy day in May. The rains are usually heavy. May as well as January, February, March, and April is considered the most uncomfortable time to visit Bontang.