Nepal is one of the best destinations for the trekking and expeditions. The rainy or summer season is not suitable in most of the trekking routes because of the rain. Nevertheless, Dolpo region towards northwest of Dhaulagiri does not receive rain as this region falls behind the Himalayas. So, Dolpo as well as Mustang are only the rain shadow areas in Nepal. So, trekking can be organized in this area even in summer.
Trekking season starts from the month of May and ends by the end of November in Dolpo and Mustang region. Though, the season starts from May there are some routes for easy treks that can be done before May too. Trekking in these regions are all organized ones. A single person does not get the permit for this region. In the case of Dolpo most of the trekkers are, French, Europeans, Americans and very few from the Asian countries.