An annual harvest and cultural celebration that brings together all the people of Kerala, Onam is based on the Panchangam, a Hindu almanack. It falls on the 22nd nakshatra, Thiruvonam, in the month of Chingam of the Malayalam calendar between August and September, according to the Gregorian calendar.

The story of Onam begins with King Mahabali, or Maveli, often described as the benevolent and just ruler under whose reign Kerala witnessed its golden age. He is said to be the grandson of the Vishnu devotee Prahlada. The history of Onam traces back to the Puranic legend of Hiranyakashyap, Holika and Prahlada's unwavering dedication to Lord Vishnu. King Mahabali’s reign was the era where equality prevailed, with no discrimination or poverty. Due to this, the Gods felt threatened by King Mahabali’s popularity and requested Lord Vishnu to curb his powers. As a faithful devotee of Lord Vishnu, King Mahabali knew Vishnu would not give in to the wishes of the other gods. As this happened, to mark his victory over the gods, Mahabali declared that he would perform a yajna or ritual and grant anyone any request during the yajna. It is believed that Lord Vishnu took his fifth avatar as Vamana, a dwarf Brahmin, to subjugate the king cleverly. The King offered the little boy anything, from gold to cattle to food and villages, anything he wished for. In response, all Vamana asked for was ‘three paces of land’. With the nature of this wish, there was no reason the king would not easily grant it, and hence, Mahabali agreed. 

In the guise of Vamana, Lord Vishnu grew to an enormous size and covered everything Mahabali ruled over in a mere two steps. For the third, Mahabali offers his head, an act of humility shaking the grand cosmos. This act reinstated King Mahabali's devotion in Lord Vishu’s eyes, which resulted in Lord Vishnu granting Mahabali a boon. This act of humility was rewarded by the boon that granted him immortality in the hearts of his people and a visit to his kingdom once a year for the ages to come. This yearly visit is celebrated as Onam, symbolising Mahabali’s homecoming and the assurance that his rule of prosperity and fairness continues in spirit. 

The celebration spans ten days, starting with Atham and culminating in Thiruvonam. Atham marks the beginning of Onam, which is celebrated by the creation of pookalam or floral carpets. They start small and grow in size and complexity through each day of Onam. The Onam celebrations across the state start with a grand procession at Tripunithura near Kochi called Athachamayam, also referred to as Thripunithura Athachamayam. The parade features decorated elephants marching, drum beats and other music, folk art forms, floats and colourfully dressed people with masks. Chithira is the next day, adding another layer to the pookalam as a symbol of growth in festivities. The third day is called Chodi, where everyone heads out to buy new clothes and gifts, known as Onakkodi. Vishakam, or day four, marks the beginning of the plethora of competitions. Vishakam sees the boat race and dance events taking form. The famous snake boat race, Vallamkali, which happens on the Pamba River, manifests itself on Anizham or the fifth day of celebration. Other games are also played on Onam such as Kayyankali, Talappanthukali and Kutukutu. Thriketta is the day when schools and offices start closing, and families start gathering in merriment. Various cultural programs commence in community centres on Moolam. On Pooradam, or day eight, families start making small clay pyramids called the Onathappan that are decorated with devotion and worshipped. Uthradom, also known as the First Onam, is celebrated on day nine as everyone starts preparing for the feast of Onasadya. Thiruvonam is also called the second Onam, the primary day when the grand feast occurs, and legend has it that King Mahabali visits every house.

The grand celebrations of Onam stretch beyond the borders of Kerala, successfully colouring the neighbouring southern states in joy and festivities. Tamil Nadu and Karnataka, with their own significant communities, take part in the festivities, adding a local flavour to the traditional feasts, dances, and rituals. While Tamil Nadu localises the grand feast, Karnataka, especially regions like Kodagu, sees the synchronisation of Onam with their local harvest festival, increasing the magnitude of the celebration. 

The rich culture and ancestral skills manifest themselves as Kathakali and Pulikali performances gather crowds, adding a layer of drama and vibrancy to the festival. Women are seen performing the Thiruvathira Kali and Kummattikali dances.  During this celebration, their elaborate costumes and energetic dance recitals showcase scenes from Mahabali’s tale and other local myths. The Vallamkali boat races are not just a test of strength and endurance but also a community event that reinforces cream work, a true reflection of the communal spirit of Onam. 

The Onam Sadya is an integral and lavish representation of Onam. It is a veritable feast that encapsulates the culinary heritage of the region. It is a traditional vegetarian meal served on a banana leaf and made from an elaborate array of over two dozen dishes, each meticulously prepared and artistically arranged. It begins with a Parippu, a simple yet flavour-dense dal made with ghee, signifying the start of the grand meal. This is followed by a succession of main course delicacies like Sambar and Avali, as well as a variety of side dishes like thoran, olan, and pachadi. Each treat is placed in a specific order as it is served, maintaining a balance of flavours from sweet to salty to spicy, honestly treating one’s palette by creating a one-of-a-kind dining experience. The experience ends with the Payasam, a sweet rice and lentil pudding enriched with jaggery, coconut milk and mangoes, adding layers of flavour and texture to the feast. The sadya reflects the agricultural abundance of Kerala as it brings to every table an array of seasonal produce cooked traditionally as passed down through generations. 

As families get together for the festival of Onam, their traditional choices are not just a celebration of culture but a vivid tapestry of history, heritage, and craftsmanship. Every garment worn during the ten days of festivities holds deep-rooted cultural and ceremonial significance influenced dramatically by local myths, the environment, and the social status of the people. 

Women welcome the festival with the subtle elegance of the Kasavu Saree, traditionally known as the Mundum Neriyathum. It is a handwoven cream-coloured saree with an intricate gold border, making it a simple and pure marvel. The gold border, crafted meticulously with thread made of real gold, holds significance to ward off evil and bring in divine blessings. The legend behind this craft talks of ancient weavers from the village of Balaramapuram, who were said to have been bestowed with this unique weaving technique through divine intervention. 

Younger women are also seen adorned in a more breezy and easy-to-carry outfit called the Set Mundu. It is a traditional attire of Kerala and a visual manifestation of its cultural ethos and simple aesthetic. It is made of two pieces, similar to a saree, but worn with one stretch of fabric as a lower lungi and the other draped over the torso and shoulder. It is deeply rooted in Malayali tradition dating back to times when simplicity and comfort were paramount in the humid conditions of Kerala. It is made of cream or beige-coloured cotton weaves with the ornamental gold kasavu border, adding the right amount of elegance to its simplistic design and structure. 

Men are typically seen wearing a Mundu and Melmundu, also called a dhoti and jubba or kurta. The Mundu is a white or cream-coloured wrap around the waist adorned with a golden zari border. It is often similar in style and design to the women’s kasavu but different in form and function. The Melmundu is an additional cloth wrapped over the torso during the rituals to symbolise respect and dignity, particularly during the feast and temple visits for Onam. 

As the celebrations of Onam span through ten days, we see a variation in the ensembles' style, design and fabrics as they embed in themselves a reflection of the particular day’s rituals and significance. For example, during the day of Atham, the first celebration, we see a more straightforward aesthetic that aligns with the modest beginning of the pookalam designs. By Uthradom, on the ninth day, everyone is seen adorned in much richer festive attire to match the grandeur of the decor and preparations for King Mahabali's welcome.

The textile choices for the grand celebrations of Onam unfold tales of heritage and artistry with every warp and weft. Cotton and silk, the primary choice of materials woven into design marvels, are selected for their beauty and deep roots in cultural resonance. As the monsoon winds retreat, these handwoven cotton sarees, known to be airy and breathable with an extensive touch of elegance, come to life with shimmering golden zari borders, traditionally handcrafted from actual gold threads, echoing the legendary golden era of King Mahabali. 

The traditional attire during Onam is a dynamic expression of Kerala’s cultural and sartorial heritage.