January in Sibu is the rainiest, the windiest, the cloudiest, and the coldest month of the year. In January, the weather in Sibu is typically hot. Average daily high temperature in January is about 28 degrees above zero. On average, Sibu has 31 rainy days in January. The rains are usually heavy. January as well as February, March, April, and May is considered the most uncomfortable time to visit Sibu.