If you're looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Santubong: The hottest months are usually May and August, with an average temperature of 26°C, while the coldest months are January and February, with an average of 24°C. The rainiest months in Santubong are December, January, February and November, with each month seeing an average of 399 mm of rainfall.