Region
Upper Mustang is a restricted trekking area in Nepal's rain shadow, a former Tibetan kingdom around the walled capital of Lo Manthang at 3,840 m north of the Annapurna range. Treks here run 10 to 14 days and require a restricted-area permit of USD 500 for 10 days (USD 50 per extra day), plus an Annapurna Conservation Area permit (NPR 3,000). Because the Himalaya block the monsoon, Mustang receives roughly 250 to 400 mm of rain a year against 2,000 mm south of the range, which makes June to September its prime season while the rest of Nepal is under cloud.
Our guides run Mustang departures right through the monsoon, when the dry high desert is the one classic route with reliable views. The pages below cover the Upper Mustang trek to Lo Manthang and the Tiji festival departure timed to the spring monastic ceremony.
Routes
Mustang sits in a rain shadow: the Annapurna and Dhaulagiri massifs, both over 8,000 m, wring the monsoon dry before it reaches the valley, so Mustang stays walkable when the Annapurna Circuit south of it is wet and leech-ridden. Arrivals data backs the shift, with monsoon-season trekking demand rising as operators publicize the rain-shadow option. The trade is wind and dust: Mustang's afternoons blow hard up the Kali Gandaki, so mornings are the walking window.
The restricted permit at USD 500 for 10 days is the region's gatekeeper, and like Manaslu it requires a licensed guide and a registered agency to file it. Full monsoon planning is in the rain-shadow treks during monsoon guide, and the Upper Mustang permit and route detail sit on the Upper Mustang trek page.
