The Kamrup district of Assam observes the Bhatheli utsav, the events to mark the junction two months in traditional Assamese calendar. The first one event takes place in mid April simultaneously with the Rongali Bihu. This is what their spring festival. The farmers who live on the banks of the rivers Barnadi and Manas implant a tall bamboo in the fields. Then they sacrifice black goat and pigeon inside a small hut to ensure their safety. The peasant fraternity in the downstream areas also organize huge fair to mark the occasion.  

Children in the rural area in the outskirt of Guwahati take an early morning bath and cut two bamboos, cleaning and washing them to be decorated with colourful clothes. These bamboos are planted near a hut with a roof of banana leaves. The festival is believed to have been promoting peace and happiness among the people of different religions and castes.

Bhatheli is known in Nalbari and Rangiya Vaisakha. The celebration has some difference.  Early in the morning, the young men take purifying baths and cut two bamboos and to be decorated it with coloured cloth and chowries. This is followed by the celebrations with music and instruments.
The same event is called Sori or Suanri in the other parts of the lower Assam area. In Bajali area the bamboo is kept against a Banyan tree . The procedures finds a mention in the Kalika Purana. A fair in the first week of Baihag is known as Bhatheli in north Kamrup, Sori or Suanri in south Kamrup.