Nepal’s Mustang and Annapurna region showcases some of the country’s most diverse weather patterns, shaped by altitude and geography. The Annapurna ranges rise above lush valleys, while Mustang lies in a rain shadow north of the Himalayas, creating a much drier, high-altitude climate.
Image: View from Dhampus Lodge, Annapurna
Temperatures
- Spring (March to May): Days are mild and ideal for trekking, with temperatures ranging from 10°C to 20°C (50°F to 68°F) in lower valleys and cooler conditions at altitude. Rhododendrons bloom in the Annapurna foothills, adding color to the trails.
- Summer/Monsoon (June to August): While the Annapurna region receives heavy rain, with slippery trails and leeches common, Mustang remains relatively dry thanks to its location in the Himalayan rain shadow. Temperatures range from 15°C to 25°C (59°F to 77°F) in lower valleys, cooler in higher passes.
- Autumn (September to November): Peak trekking season. Clear skies, dry weather, and moderate temperatures (10°C to 22°C / 50°F to 72°F in lower valleys) make conditions near perfect.
- Winter (December to February): High-altitude areas can be snowbound, especially mountain passes. Lower valleys remain cold but trek-able, with daytime temperatures averaging 5°C to 12°C (41°F to 54°F).
Rainfall
The Annapurna region is heavily affected by the summer monsoon (June–August), receiving between 2,000 and 3,000 mm (79–118 inches) of rain annually, which can make trails muddy and challenging. In stark contrast, Mustang lies in the Himalayan rain shadow and remains arid throughout the year, with less than 200 mm (8 inches) of rainfall annually—even during the peak of the monsoon.
Snowfall
Snow is common above 2,500 m (8,200 ft) in winter, with mountain passes such as Thorong La often closed due to heavy snow from December to February. Trekkers typically favor March–May or late September–November for the best balance of accessibility and clear mountain views.
