Weather will likely play an important role when you plan your trip to Brunei, 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 26°C, while the coldest months are February and January, with an average of 25°C. The rainiest months in Brunei are October, November, December and January, with each month seeing an average of 294 mm of rainfall.