June in Sibu is the sunniest and the hottest month of the year. In June, the weather in Sibu is typically hot. Average daily high temperature in June is about 31 degrees above zero. On average, Sibu has 27 rainy, 2 sunny, and 1 partly cloudy day in June. The rains are usually heavy. June as well as January, February, March, and April is considered the most uncomfortable time to visit Sibu.