Tibet Tour From Nepal 

April to June and Oct. to Nov are the most ideal time to enjoy the best mountain view with clear skies for the scenic trek and plenty of outdoor activities.

Meanwhile, traveling between Nov and Feb is a great choice to avoid crowds in Tibet with plenty of discounts as to hotel and flight, entrance tickets. Jun to Aug. sees many fascinating festivals in Tibet with pleasant weather. It is a great time to soak up the distinctive festive vibes. Meanwhile, since it is the monsoon season in Nepal that often brings heavy rain, muddy road and landslide, esp. at Sino-Nepal border. So, traveling by air or Tibet train to Lhasa is highly recommended.