Onam comes in the month of "Chingam" which is the first month according to the Malayalam Calendar. People put flower mats in front of their houses, to welcome King Mahabali. There will be competition for the laying of flower mats; Keralites all over the world will be celebrating this ten days with pomp and gaiety. They wear new dresses, visit as many temples as they can, perform dances like Thiruvadhira kali, Thumbi Tullal etc. to name a few.

Onam is celebrated with a focus on different cultural aspects at different places. Athachamayam- a cultural procession takes place in the royal town of Tripunithura near Ernakulam-Kochi, on the Atham day of Chingam, which also marks the beginning of Onam celebrations. At the Vamanamoorthy temple in Thrikkakara, the annual temple festival coincides with Onam. The temple is dedicated to Lord Vamana and is directly linked to the mythological background of Onam.

Onam Pookkalam is considered as a symbol for secularism. Various kinds of flowers combine together to form a great-looking pookkalam. So, it shall reflect those old good days during the rule of King Mahabali. It's a great pleasure for the people of Kerala to make Pookkalam from Atham to Thiruvonam, especially for children.

The celebrations begin within a fortnight of the Malayalam New Year and go on for ten days. The last day called the Thiruvonam is the most important. All over the state, rituals along with new clothes, traditional cuisine, dance, and music mark this harvest festival.

At Valluvanad(mainly Ottapalam, Shornur regions), Kathakali dancers in gorgeous costumes enact the legends. A strikingly impressive procession of caparisoned elephants is taken out at Thrissur, where masked dancers also go from house to house performing the colorful Kummattikali dance. At Cheruthuruthy, people gather to watch Kathakali performers enact scenes from epics and folk tales. Pulikali, also known as Kaduvakali is a common sight during Onam season. Performers painted like tigers in bright yellow, red and black, dance to the beats of instruments like Udukku and thakil.

At Aranmula, during Onam days the famous Aranmula Vallam Kali is conducted.

The swing is another integral part of Onam, especially in the rural areas. Young men and women, decked in their best, sing Onappaatt, or Onam songs, and rock one another on swings slung from high branches.