If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Santubong: The hottest months are usually May and August with an average temp of 78°F, while the coldest months are January and February with an average of 76°F. The rainiest months in Santubong are December, January, February, and November, with each month seeing an average of 16 inches of rainfall.