Onam: What, Why, When, How

What it is

Onam is Kerala's great harvest festival, kept in the Malayalam month of Chingam, after the monsoon rains, when the fields are full and flowers are everywhere. Its high point is Thiruvonam, the day of the Thiruvonam (Shravana) nakshatra. The festival welcomes back Mahabali, the beloved king of Kerala's old stories, who is said to visit his people once a year.

The celebrations build over about ten days, from Atham to Thiruvonam. Each morning families add a ring to a flower carpet (pookalam) at the door. Elders give new clothes (onakkodi). On Thiruvonam families set up clay figures of Thrikkakara Appan, worship them, and sit down to the Onam feast (Onasadya) on banana leaves. Boat races (vallam kali), tiger dances (pulikali), the women's Thiruvathira dance and swings hung from trees fill the days.

Onam is shared by Malayalis of every background, in Kerala and around the world, where Malayali associations hold their sadyas and cultural programmes, often on a weekend near the day.

Why it is kept

Mahabali, the good king. Mahabali, or Maveli, was an asura king, the grandson of Prahlada. Kerala remembers his reign as a golden age, when everyone was equal, no one was poor or hungry, and no one lied or cheated. His goodness and his power grew so great that the gods grew uneasy.

Vamana's three steps. The Bhagavata Purana (book 8, chapters 15 to 23) tells how Vishnu came to Bali's great sacrifice as Vamana, a small Brahmin boy, and asked for only as much land as he could cover in three steps. Bali, who never refused a guest, agreed, though his teacher warned him. Then Vamana grew to fill the universe: with one step he covered the earth and with the second the heavens. For the third, Bali bowed and offered his own head. Vishnu placed his foot there, sent Bali to rule the beautiful underworld of Sutala, and blessed him for his truthfulness. The Rig Veda already praises Vishnu's three strides; in R. T. H. Griffith's translation, “Through all this world strode Vishnu; thrice his foot he planted, and the whole / Was gathered in his footstep's dust” (Book 1, Hymn 22).

The yearly visit. Kerala tradition adds that Bali asked to visit his people once a year, and that his wish was granted. Onam is that visit: homes are cleaned, flowers are laid at every door and everyone eats well, so that the king finds his people as happy as in his own time. Families honour both Mahabali and Vamana, and the Vamana temple at Thrikkakara is at the heart of the festival.

Harvest and new year. In most of Kerala, Chingam is also the first month of the Malayalam calendar, so Onam comes at the start of the Malayali year, with the harvest in.

The texts behind the story

• Bhagavata Purana, book 8, chapters 15–23 (Bali and Vamana). Summarised in our own words.
• Rig Veda, Book 1, Hymn 22, stanza 17 (Vishnu's three strides). R. T. H. Griffith (tr.), The Hymns of the Rigveda, vol. 1 (Benares: E. J. Lazarus, 1889). Griffith died 1906: public domain. Quoted verbatim. (Book I, Hymn XXII, stanza 17, p. 36)
• Mahabali's yearly visit and the golden age of his reign: Kerala tradition and folk song. Summarised in our own words.

When it is kept

Thiruvonam is the day in the Malayalam solar month of Chingam (the Sun in Simha) on which the Thiruvonam nakshatra, called Shravana elsewhere, is present at sunrise at your location. The Malayalam month itself begins by the Malayali rule: if the Sun enters Simha before three-fifths of the daytime has passed, the month begins that day; otherwise the next day. Atham, the first of the ten days, is the day of the Hasta nakshatra, about nine days before Thiruvonam.

The date, from the calendar engine

• Onam 2027: Thiruvonam falls on Sunday, September 12, 2027 in Washington DC (Malayali rule, computed for this city). The date is the same in New Delhi.

The date depends on your city. Every city we cover is on the year page.

Traditions and regional customs

• Malayali: Thiruvonam nakshatra at sunrise in the solar month Chingam
• Kerala almanacs: may also require the nakshatra to last a minimum time after sunrise
• Thrikkakara (Vamana temple): the ten-day festival from Atham

Why the day can differ

Thiruvonam is decided by the nakshatra at sunrise, so cities in different time zones can keep it on different dates, and families abroad can differ from Kerala by a day. Some Kerala almanacs also ask that the nakshatra last for a minimum time after sunrise; the app uses the nakshatra at sunrise alone, so in a rare year a Kerala almanac may name the next day.

The other days of the celebration follow the nakshatras that come before Thiruvonam, from Atham, so their exact count can be nine to eleven days. Malayali associations abroad usually hold the Onam sadya and programme on a weekend near Thiruvonam.

How to keep it at home

1. From Atham, make a pookalam at the door each morning: start with one small ring of flowers and add a ring each day, so that it is largest on Thiruvonam. Use petals, leaves and flowers that are easy to find where you live.
2. On Uthradam, the eve, prepare for the feast. Elders give new clothes (onakkodi) to the family.
3. On Thiruvonam morning, bathe and wear new clothes. Place the clay figures of Thrikkakara Appan (Onathappan; families differ on whether they stand for Vamana, for Mahabali or for both) on the pookalam, decorate them with flowers, light the brass lamp (nilavilakku), and offer flowers and ada, a sweet of rice-flour dough steamed in a leaf. Many families pray to Vishnu as Vamana, with "Om Namo Narayanaya" or verses of the Narayaneeyam.
4. At midday, serve the Onasadya on banana leaves, with the dishes placed in their customary order, and eat together. Afterwards, play, swing, sing Onam songs and visit family and friends.

Fasting

Onam is a feast, not a fast. The custom is to eat the sadya together and to share it; many families also feed guests, neighbours and anyone who comes to the door.

Food

The vegetarian Onasadya has many dishes: rice, parippu (dal) with ghee, sambar, rasam, avial, thoran, olan, kalan, pachadi, kichadi, inji puli, banana chips and sharkara varatti, pappadam, pickles and buttermilk, and payasam, above all ada pradhaman and pal payasam.

For children

Long ago, Kerala had a kind king called Mahabali. In his time everyone was happy and everyone shared. One day a small boy named Vamana asked him for just three steps of land. The king said yes, and the boy grew bigger and bigger, until his steps covered the whole world. The king bowed and kept his promise, and he was given a beautiful kingdom of his own. Once a year he comes back to visit his people, and on Onam everyone makes flower carpets and a big feast to welcome him.

Something to do together

Make a small pookalam together on a tray or a sheet of paper: a circle of petals, leaves or paper shapes. Add one new ring every day until Thiruvonam.

Sources

• Panchang engine rule onam (packages/panchang/data/festivals.json), with the sources it lists and its note on the minimum-duration rule in Kerala almanacs.
• N. Dershowitz and E. M. Reingold, "Indian Calendrical Calculations" (§4, the Malayali rule for the start of a solar month).
• R. T. H. Griffith (tr.), The Hymns of the Rigveda, vol. 1 (Benares, 1889), Book 1, Hymn 22. Public domain.
• Wikipedia, "Onam" (the ten days, Thiruvonam and the yearly return of King Mahabali).
• Kerala Tourism (Government of Kerala), "Thrikkakara Charitham" (the ten-day celebration from Atham to Thiruvonam in Chingam, and the Vamana temple at Thrikkakara).

Related guides

• Vishu (Malayali New Year)