Weather is probably a major factor when you plan your trip to Dieng, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually October and May with an average temp of 74°F, while the coldest months are August and July with an average of 72°F. The rainiest months in Dieng are November, December, February, and April, with each month seeing an average of 24 inches of rainfall.