Weather is probably a major factor when you plan your trip to Jaru, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually September and August with an average temp of 82°F, while the coldest months are June and July with an average of 78°F. The rainiest months in Jaru are January, February, March, and December, with each month seeing an average of 14 inches of rainfall.