Spring and autumn are the best seasons to visit Nepal for any kind of tourism, travel and climbing activities. The weather becomes clear in these seasons and you can see the wonderful views. In Trekking, it is the suitable time to walk and ascending in the high altitude. In monsoon, it rains a lot and there is the possibility of several landslides and streams become enormous. But, monsoon is the best seasons to travel in Dolpo and Mustang region, which is the best area to trek in monsoon. Winter is a tough season to trek in the Himalayan region, however the trek and tour in the lowland region is possible.