Weather is probably a major factor when you plan your trip to Siwalankerto, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually October and September with an average temp of 83°F, while the coldest months are July and August with an average of 82°F. The rainiest months in Siwalankerto are January, February, December, and March, with each month seeing an average of 12 inches of rainfall.