Onam is celebrated at the beginning of the month of Chingam, the first month of the solar Malayalam calendar (Kollavarsham). It falls in August or September each year.
The festival is spread over 10 days and culminates with Thiruvonam, the most important day.
The festival is celebrated to welcome King Mahabali, whose spirit is said to visit Kerala at the time of Onam.
It is also celebrated as the festival of paddy harvest.
During the festival, people take part in a variety of group activities such as the Pookolam (rangoli made with fresh flowers), Vallam Kali (boat race), Pulikali (tiger dance), Kai Kottu Kali (Onam dance), Kummattikali (mask dance) and various other activities.
