When to go? it is possible to hike in the exotic ring of fire Indonesia throughout the year, the conditions are at their best during dry season, late April to early October when the rain is not that much and the air drier.
The average temperatures at some mountains are refreshingly cool during the day but outright cold at night as temperatures can drop to zero in the dry season and are rarely much above 5°C in wet season.
The choice of hiking routes is vast: ranging from gentle walks to extreme treks, like 2-3 weeks mountain climbing expedition through dense tropical jungle.