Weather is probably a major factor when you plan your trip to Sibu, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually May and August, with an average temperature of 27°C, while the coldest months are February and March, with an average of 26°C. The rainiest months in Sibu are December, January, November and October, with each month seeing an average of 340 mm of rainfall.