Planning for the weather is a good way to make your trip to Batu Karas relaxing and enjoyable, especially when you're splurging. The hottest months are usually March and April, with an average temperature of 26°C, while the coldest months are August and September, with an average of 25°C. The rainiest months in Batu Karas are January, December, February and March, with each month seeing an average of 389 mm of rainfall.