Taking into account the local weather in Batu Karas is an important factor for planning your visit, especially if you plan to spend your trip poolside. The hottest months are usually March and April with an average temp of 78°F, while the coldest months are August and September with an average of 76°F. The rainiest months in Batu Karas are January, December, February, and March, with each month seeing an average of 15 inches of rainfall.