Thula Utsavam is a month long festival that takes place every year at Mayiladuthurai. The festival during the Holy month of Aippasi (between mid-October and mid-November) sees thousands if not lakhs of devotees visit Mayiladuthurai. Similar to the Kumbh Mela in the North, Thula Utsavam on the banks of the river Cauvery draws devotees from South India. The last day of the Holy month Aippasi, Kadaimugam is a celebration unlike any other. It is believed that the Holy Rivers Ganges, Yamuna and Saraswathi come to the mighty Cauvery for a cleansing ritual such that they may be recharged and ready to imbibe the sins of the believing devotees who take a dip in their waters. A holy bath on this day is of significance to devotees as the four holy rivers are said to converge in one place.
The day before the Holy month of Aippasi ends, chariot festivals reign the streets of Mayiladuthurai. Deities from the Vallalar temple, Mayuranathaswami temple and Ranganathaswami temple are taken around the town in chariots that are decorated specifically for the occasion.