The Losar Festival :  (held in Feb/March - in Dirang, Tawang, Bomdila and surrounding villages):

The losar festival of the Monpas, which is their new year, is celebrated for five days. On the eve of the festival people clean out their homes to usher in the new year and discard the old. The dirt and grit of the old year is considered to symbolize ill health. During the five days of festivities prayers are offered for prosperity and good health, the festivities include the hoisting of religious flags atop their homes; visits to the homes of friends and relatives; holy Buddhist scriptures are read in every home and butter lamps are lit in houses and the campuses.

The Reh Festival :

Appeasement of the deities who control the peace and prosperity of the people is through behind the six day celebrations of the Reh festival, essentially associated with the Idu Mishmis. The festival comes to an end with great fanfare and the priest dance performed during the six days is its special attraction.

The Ojiyale Festival : (March- April)

The wanchos celebrate their most popular festival, Ojiyale during March - April, for a period of six to 12 days interspersed with prayer, songs and dance. Villagers exchange bamboo tubes of rice beer as a mark of greeting and goodwill. Pigs' skin is offered to the village chief as a mark of respect.

The Tamladu Festival :  (February 15 - held at Tezu)

Another important festival is Tamladu, essentially celebrated by the Digaru Mishis tribe. During the festival, prayers are offered to the god of the earth and the god of the waters for protection against natural calamities. The supreme - Lord Jebmalu, is worshipped for the prosperity and welfare of human being, the standing crops and domestic animals.

The Khan Festival :  (February in Bomdilla)

Another is the Khan festival, an occasion for the reunion of the people. Besides the usual festivities, the significance of the festival lies in the ceremony whereby the priest ties a piece of wool around everybody's neck. The belief is that the enchanted thread will bring good luck to each of them.

The Sanken Festival : (April 15 in Tezu)

It is an occasion to bathe the images of Lord Buddha ceremoniously. This also heralds the new year and people sprinkle water on each other a sign of merriment.

The Mopin Festival : (April 5, 6  Itanagar, Daporijo, Along, Pasighat)

One of the groups celebrate Mopin for wealth and prosperity as also good health and universal happiness. Smearing of rice powder on each others faces marks the beginning of the festival which is celebrated for five days.

The Mol festival of the Tangsas is celebrated for three days to welcome the new year.

Losar is the New Years’ Celebration of the Monpas. During the five days of festivities, prayers are offered, religious flags are hoisted atop their homes; Buddhist scriptures are read in every home and butter lamps are lit in houses and the campuses. Reh is essentially associated with the Idu Mishmis, the six- day celebrations’ special attraction is the Priest dance. During Tamladu, the Digaru Mishmis offers prayers to the God of the Earth and the God of the Water. The supreme God Jebmalu is also worshipped. Khan is significant because of a ceremony where the priest ties a piece of wool around everybody’s neck. During Sangken, people sprinkle water on each other as a sign of merriment. Smearing of rice powder on each other’s face marks the beginning of the five- day celebrations of Mopin.

From highly stylised religious dance- dramas of Buddhists to the martial steps and colourful performances of the Noctes and Wanchos, dances here are the source of real joy. Teams of young girls in perfect rhythmic unison perform the Ponung dance of the Adis. Similar group dances in colourful costumes are performed in the Upper and Lower Subansiri

Festivals form an essential aspect of the socio-cultural life of the people of the state. As a matter of fact, festivals are the mirror of the people's culture. Since agriculture is the mainstay of the population, naturally the festivals celebrated by the people are closely connected with their occupation. Such festivals are celebrated at a larger scale for thanking the gods for their providence and for saying a prayer for a bumper crop. Throughout the year festivals are celebrated by one or the other tribe. Some of the important festivals are Solung, Mopin, Losar, Boori Boot, Dree, Nechi Dau, Khan, Kshyatsowai, Loku, Longte Yullo, Moi, Nyokum, Ojiale, Reh, Sanken, Si-Donyi and Tamladu.

Animal sacrifices are a common ritual in most of the festivals, particularly in the Non-Bodic tribes. The festivals have been firmly blended with the lifestyle of the people of Arunachal Pradesh. For some communities like the Mijis these are the occasions to bring all people together who might otherwise be scattered in far flung villages. This serves as a reminder of the richness of their cultural heritage.

The spring time festivals are celebrated during the period from January to April by the different groups. In the celebrations of these festivals, the religious rites and the sacrifices are generally performed by their priests assisted by some select male members.