South Indian state of Kerala is a land that is also considered as the land of the God himself owing to its spectacular beauty and amazing environs. Though picturesque all throughout the year due to its lush palm trees, clear blue waters and open skies, the land of Kerala becomes all the more lively and exuberant when the festival of Onam is on. All throughout the days till the festival is celebrated, this Indian state is simply overjoyed, pepped up with energy and rejoicing each and every moment of life to its best possible.
Onam is the biggest and the most important festival of the state of Kerala. It is a harvest festival and is celebrated with joy and enthusiasm all over the state by people of all communities. It is celebrated at a time when everything appears so nice and good. The beautiful landscape of Kerala can be seen in its full radiance at this time of the Malayalam New Year. Weather, it seems, also seeks to be a part of the festival. It contributes by becoming pleasantly warm and sunny. Fields look brilliant with a bountiful harvest. Farmers feel on top of the world as they watch the result of their hard labour with pride. According to a popular legend, the festival is celebrated to welcome King Mahabali, whose spirit is said to visit Kerala at the time of Onam.
Onam is celebrated in the beginning of the month of Chingam, the first month of Malayalam Calendar (Kollavarsham). This corresponds with the month of August-September according to Gregorian calendar. Onam lasts from four to ten days. First day, Atham and tenth day, Thiruonam are most important of all.
The Origin of Onam
Onam or Thiruonam originated as a joyous annual reminiscence of the golden rule of King Mahabali, a mythical king, who ruled Kerala a very long time ago. It recalls the sacrifice of the great king, his true devotion to God, his human pride and his ultimate redemption. Onam welcomes the spirit of a great king, and assures him that his people are happy and wish him well.
The Legend
It is believed that there once lived a wise and generous asura (demon) king, Mahabali. He was highly regarded by his subjects and everybody was happy in in his kingdom.
Gods felt challenged with the growing popularity of Mahabali. They seeked help from Lord Vishnu who was worshiped by King Mahabali. Lord Vishnu took the avatar of a poor and dwarf Brahmin, called Vamana and came to the kingdom of Mahabali just after his morning prayers, when the King gave boons to the Brahmin. The disguised Lord Vishnu asked for as much land as could be covered by his three steps. The King made a promise to do so. Suddenly, Vamana increased to a massive size. With his one step he covered the whole of the sky and with the other he covered the whole of earth. He then asked for a place to put his third step. King realised that the boy was no ordinary Brahmin and asked Vamana to to put his third step on his head.
The boy did so, pushing Mahabali in the nether world, the patala. Lord Vishnu was pleased with King Mahabali generosity and granted him a boon. Deeply attached with his people, the King said he would like to visit Kerala and his people every year. Lord Vishnu was pleased to grant the request.
It is this homecoming of King Mahabali that is celebrated as Onam every year.
The Custom 
A flower carpet called ‘Pookalam’ is laid in front of every house to welcome the advent of the vanquished king, and earthen mounds representing Mahabali and Vishnu are placed in the dung-plastered courtyards. Traditional rituals are performed followed by a lavish feast called ‘Sadhya’. Onam also means new clothes for the whole family, sumptuous home-cooked delicacies on plantain leaf and the lingering aroma of the sweet Payasam.
Festival of Onam
Although this festival has its origin in Hindu mythology, Onam is for all people of all class and creed. Hindus, Muslims and Christians, the wealthy and the downtrodden, all celebrate Onam with equal fervor. The secular character of Onam is peculiar to this land where unity had always coexisted with diversity, especially during festivals, when people come together to celebrate life’s unlimited joys.