Plizio Visual Lab

Thorthormi Tsho

Plizio editorial teamUpdated: Jun 2026Data Sources

Lake

Weather…

Thorthormi Tsho is a high-altitude glacial lake in the remote Lunana region of northern Bhutan. It is located at an altitude of over 4,400 meters and is part of a complex of several supraglacial lakes. The lake has gained international attention as it is considered one of the most dangerous glacial lakes in the world. Due to global warming, the surrounding glaciers are melting rapidly, causing the lake to grow and increasing the pressure on its unstable moraine dams. An outburst from Thorthormi Tsho could trigger catastrophic Glacial Lake Outburst Floods (GLOFs) in the Pho Chhu valley and beyond. To mitigate this danger, Bhutan, with international support, has launched a challenging project to manually lower the lake's water level by digging a drainage channel. This project at extreme altitude is a symbol of Bhutan's fight against the impacts of climate change.

Location: Bhutan
Nearby: Sarpang (4 km)

Best time to visit & climate

The most pleasant time to visit is Jun, Sep, Oct.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Avg °C	-10	-8	-6	-2	2	6	7	6	5	0	-4	-7
Rain mm	3	8	20	36	63	91	168	140	72	27	2	2

📋 Practical info

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Getting there

Reaching this expanding glacial lake consistently requires a grueling, multi-day trek deep into the High Himalayas. The trails are notoriously difficult and demand significant logistical preparation to attempt safely.

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Best season

The viable trekking window is typically restricted to a few clear weeks in autumn, usually around October. During other seasons, severe weather, heavy snow, or monsoon rains make the area functionally inaccessible.

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Terrain & paths

The severe environment strictly consists of precarious ice fields, rocky moraines, and high-altitude scree. The landscape is constantly shifting due to rapid glacial melt and ongoing climate change impacts.

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What to bring

Visitors strictly need specialized high-altitude trekking gear, including dense thermal layers, heavy-duty boots, and emergency sleeping bags. UV protection is also critical due to the intense solar radiation at altitude.

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Parking

All motorized transport effectively ends many days' walk from the lake at remote valley trailheads. Extensive pack animal trains are inherently required to transport provisions from the nearest functional road.

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Safety

The structural risk of glacial lake outburst floods is critically high, strictly necessitating absolute adherence to safety protocols. High-altitude sickness and sudden severe storms remain ever-present, fatal dangers.

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Time needed

Organized expeditions to observe this lake generally demand at least two to three weeks of continuous trekking. Time spent directly at the vulnerable, freezing lakeshore is usually brief and very carefully managed.