The Rinjani trek is a challenging mountain walk and you must be prepared with good equipment, warm and windproof clothing. Rinjani can attract severe storms, lightening and strong winds. When the weather is settled, the sun is intense and the nights frosty.
Parts of the trail are steep and slippery. Beware of bad weather and risks of exposure to the wet and cold (hypothermia). If caught in an electrical storm, take shelter and avoid prominent ridges. Beware of stinging insects and plants. Leeches can be a nuisance in the wet season.
Although Mt.Rinjani has not erupted in recorded history, Mt.Baru (2,351m) in the crater lake is an active volcano. It last erupted dramatically in 1994. Check the notice boards for recent hazards, and take advice from park staff and guides.
Fresh water springs are a feature of the trek and determine campsites. Your guide know where these are. During the drier months (July – September) some springs completely disappear. Park staff and guides constantly monitor these water sources to determine their abundance.