Mount Bosavi
Mountain Extinct volcanic massif in PNG famed for rich biodiversity
An extinct volcanic caldera in Papua New Guinea, Mount Bosavi holds dense rainforest and documented endemic species; visitors join biodiversity expeditions and multi‑day jungle treks.
Mount Bosavi is an extinct volcano in Southern Highlands Province of Papua New Guinea that collapsed to form a broad forested caldera. The caldera and its intact montane rainforest are known for high levels of endemic biodiversity and species discoveries.
The caldera supports primary rainforest habitat and has been the focus of biological expeditions and surveys, most prominently a 2009 scientific expedition that documented several species not previously known to science. Researchers and experienced expedition groups visit for biodiversity surveys and remote-area trekking.
Mount Bosavi formed through volcanic activity before becoming inactive and collapsing to create the caldera that exists today. The mountain and its ecosystems have remained relatively undisturbed due to the remoteness of the site and limited access.
The mountain sits inland in the rugged interior of Papua New Guinea’s Southern Highlands Province, reached only by overland travel from local settlements and requiring careful logistical planning for scientific or guided visits.
- Biodiversity discovery: A notable 2009 biological survey documented multiple species new to science, attracting biological research interest.
- Access: Access requires organized expeditions and multi-day treks from nearby settlements; there is no regular tourist infrastructure.
What to See #
- Caldera: A large, forested collapsed volcanic crater that contains intact montane rainforest and steep rim walls, hosting most of the mountain's endemic wildlife.
- Rim and approaches: Rim and slopes where trails and approaches end, used by scientific teams for access to the interior and wildlife surveys.
How to Get to Mount Bosavi #
There is no commercial transport directly to Mount Bosavi. Typical access begins with a flight to Port Moresby, then onward charter or domestic flight to a regional airstrip (Kiunga, Tabubil or Tari are common staging points) depending on the operator. From the airstrip, travel is by river boat and multi-day trek through rugged jungle. All visits must be arranged with local landowners and an experienced PNG operator; independent attempts are strongly discouraged.
Tips for Visiting Mount Bosavi #
- Arrange an expedition through a well-reviewed PNG operator - independent treks are unsafe and disrespectful to customary landowners.
- Bring a satellite phone or reliable comms - mobile coverage is non-existent once the trek begins.
- Prepare for leeches, deep mud and sudden, heavy rain; gaiters and a waterproof pack cover are essential.
- Ask permission and a guide from the Bosavi clan councils; scientific and tourist access are controlled by local landowners.
Best Time to Visit Mount Bosavi #
Visit in the dry season for safer trekking and more reliable logistics; expect an intensely wet, green landscape outside those months.
Weather & Climate near Mount Bosavi #
Mount Bosavi's climate is classified as Oceanic - Oceanic climate with consistently warm temperatures year-round. Temperatures range from 14°C to 26°C. Heavy rainfall (3480 mm/year), wettest in March, distributed fairly evenly throughout the year.
January
January is mild with highs of 25°C and lows of 15°C. Heavy rain (326 mm).
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February
February is the warmest month with highs of 25°C and lows of 15°C. Heavy rain (320 mm).
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March
March is mild with highs of 25°C and lows of 15°C. The wettest month with heavy rain (381 mm).
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April
April is mild with highs of 25°C and lows of 15°C. Heavy rain (279 mm).
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May
May is mild with highs of 25°C and lows of 15°C. Heavy rain (297 mm).
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June
June is mild with highs of 24°C and lows of 14°C. Heavy rain (247 mm).
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July
July is mild with highs of 23°C and lows of 14°C. Heavy rain (247 mm).
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August
August is mild with highs of 23°C and lows of 14°C. Heavy rain (231 mm).
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September
September is mild with highs of 24°C and lows of 14°C. Heavy rain (241 mm).
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October
October is mild with highs of 24°C and lows of 14°C. Heavy rain (321 mm).
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November
November is mild with highs of 26°C and lows of 14°C. Heavy rain (260 mm).
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December
December is mild with highs of 25°C and lows of 15°C. Heavy rain (330 mm).
