Weather is probably a major factor when you plan your trip to Sibolga, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually May and June, with an average temperature of 26°C, while the coldest months are July and January, with an average of 26°C. The rainiest months in Sibolga are November, December, March and October, with each month seeing an average of 491 mm of rainfall.