The best time to visit Tawang is from April to October. Spring (April–June) brings rhododendron blooms on the hillsides and clear views of the Himalayan peaks before the monsoon arrives in June. The monsoon months (June–September) make the roads muddy and sometimes impassable, but the landscape is brilliantly green and the waterfalls are at their fullest. October brings post-monsoon clarity and golden light.
The Torgya Festival in January is one of the most important Buddhist festivals in the eastern Himalayas, with three days of masked dances performed by monks in the monastery courtyard. It is worth timing a visit around if you can handle the cold — temperatures drop well below freezing at night.
Winter (November–March) is bitterly cold, with the Sela Pass frequently snowbound. Some guesthouses close, and the mountain roads can become dangerous. If you visit in winter, carry warm clothing regardless of what the Guwahati weather looked like when you set out.