January
Duruthu Perehera
This colorful festival commemorates the Buddha’s visit to Kelaniya in the eighth year following his Enlightenment (535 BC). The procession commences and culminates at the Kelaniya Raja Maha Vihara, Temple, located some 7 miles northeast of Colombo. It is a colorful pageant with elephants, dancers and drummers whip crackers attracting thousands of spectators. The procession (Perahera) is held for three nights in the month of January. Furthermore, the Kelaniya dagoba, unusual for its paddy heap design is attributed to King Yatala Tissa (3 rd Cent. BC): and the temple is renowned for its intricate wall paintings and murals.

(Source: www.southasianmedia.net)
See: http://travelpuppy.com/sri-lanka/colombo/tours-excursion.htm
Thai Pongal
This is a festival of Hindus. It celebrates the harvest and honors the Hindu sun deity. This festival is culturally celebrated on the 14th or 15th of January each year. It is marked by many observances, including the ceremonial preparation and consumption of traditional sweetened and spiced rice called ‘pongal’. 'Pongal' in Tamil means boiling over. After worshipping at a Hindu temple, a large pot of rice is cooked in spicy, sweetened milk and left to boil over. The direction of the spilling will indicate good or bad luck in the coming year. In rural areas it is followed immediately after by ‘madu pongal’, which concentrates domestic livestock.

(Source: www.southasianmedia.net)
February/March
Independence Day
Though this is not a cultural event, the celebrations with full of pomp and pageantry mark the anniversary of Independence from Great Britain in 1948. Independence Day celebrations on the 4th of February every year hybrids and embraces with various cultural shows and activities. Celebrations are held throughout the Island on this day.

(Source:www.usla.co.nz/PhotoAlbum/)
Navam Perahera
This is undoubtedly Colombo’s grandest outdoor parade, with a splendid display of Sri Lanka’s traditional forms of art: including performances by rhythmic dancers and drummers from around the island in a procession of over 100 caparisoned elephants. This Perahara (pageant) includes both Udarata (Up-country) and Pahatharata (low-country) dances.
See: http://www.mysrilanka.com/travel/lanka/art/dancing.htm
Remembering the appointment of the Lord Buddha’s two close disciples in the pre-Christian era, the Gangaramaya Temple, a beautiful lake-side temple in Colombo, located in a colorful peripheral area, celebrates this incidence in this month every year.
The street of Colombo transform under the weight of 100 colorful elephants during February’s full moon. The Navam Perehara, which started in 1979, attracts more than a million spectators every year to the gangaramaya temple, at Hunupitiya on the banks of the picturesque Beira Lake. The event usually has as many as 1000 performers.
Maha Sivarathri
This is held in late February or early March, this festival commemorates the union of Lord Siva with his consort Goddess parvathi. Ceremonies involving prayers takes place mostly at nights. Though, both men and women celebrate Shivaratri, it is an especially auspicious day for women. Married women pray for the well being of their husbands and sons, while unmarried women pray for a husband like Shiva, who is considered to be the ideal husband. On the day of the festival, people will fast and spend the day focused on Shiva, meditating and chanting "Om Namaha Shivaya."
April
Sinhala and Tamil Traditional New year
Sri Lanka’s two main ethnic groups – the Sinhalese and Tamils – celebrate a common New Year coinciding with the passage of the Sun from Pisces to Aries in April. Sinhala and Tamil New Year signify the beginning of the New Year for both Buddhists and Hindus. It marks the completion of the solar circuit and is celebrated around the second week of April. New clothes are worn and horoscopes are foretold.
The dawn of the New Year is celebrated with the observance of age-old customs, folk dances and theatre, and the playing of traditional games in every village and hamlet. Special food and sweetmeats are a delightful feature of this event (See: http://www.lankalibrary.com/rit/avurudu).
The beautiful festivals and processions in different Kovils or Hindu Temples in the province can be seen in April.
Money is exchanged among families and friends in a tradition known as 'ganu denu'. Special food items and sweetmeats are prepared and in the villages various New Year games are played. It is a day spent in rituals and fun-filled activities. Villagers’ Raban playing (See: http://www.info.lk/srilanka/sightsandsoundsofsrilanka/srilankanmusicandsounds/) is one of beautiful games indicating the peaceful and harmonious lifestyle of the villagers.

(Source: www.southasianmedia.net)
In April, Great Friday is celebrated specially at churches located in Chiritians and Chathelic communities living areas in the Western Province.
May/June
Mayday is still a very celebrated event in Sri Lanka. Celebrating International Labor Day by observing the day with a variety of marches and other events, particular in Colombo city is the most important political day of the year.

(Source: www.southasianmedia.net)
Vesak
A trice blessed day for Buddhists, Vesak commemorates the birth, enlightenment and passing away of the Buddha. With a series of festival, Vesak is celebrated with a blaze of lights, lanterns and huge illuminated displays known as pandols, as well as with street-plays, pantomimes, pageants and food/drink donations on roadside booths at which free refreshments are distributed to all passers by. Most beautiful pandols in Colombo and sub-urban areas are located in Colombo Fort, Thotalanga, Dematagoda, Jayawardanapura, Kalaniya and Borella. Wesak lanterns, alms-giving fares, chanting scriptures, and practicing religious and spiritual activities can be seen every places in the province during this period.

(Source: www.southasianmedia.net & http://www.lankalibrary.com/rit/vesak.htm)
Poson Festival
It is celebrated in June in the country. This day commemorates the introduction of Buddhism to Sri Lanka by Venerable Mahinda, son of emperor Ashoka of India. The Western Province celebrates this event by erecting decorated pandols, making colorful lanterns, alms-giving fares, chanting stanzas and practicing religious and spiritual activities.

(Source: www.southasianmedia.net)
July/August
Esala Perahera
This is a month of religious celebrations in many parts of the Island. Besides in Kandy, Kataragama, Devinuvara, similar pageants are conducted at Kotte and Bellanwila in the Western province. It is a traditional event descending from the past. These festivals are organized to remember the Lord Buddha’s renunciation of worldly indulgence as a king as the first step to attain Buddhahood.
Nawagamuwa Asala Perahara
This procession was originated during the reign of the King Gajabhaya. The Perahara has its uniqueness because bulls are taken into march by this procession only. The historical reason for such inclusion was that the cattle began to die in large numbers for some unknown reason in one olden period. The farmers believed it was because of the anger of deity and included bulls to the procession.
Kotahena Asala Perahara
The Kotehena Parama Kanda Viharaya orgernizes this procession and the history of this temple goes back 190 years back. It is a well illuminated procession with lots of traditional dancing and religious practices with a large number of elephants.
Nikini Perahara
In August, Nikini Perahara is organized at Kotte Rajamaha Viharaya (temple). The event is organized to commemorate an olden period in which the temple was blessed by reposting Lord Buddha’s tooth relic in a special shrine.
Vel Festival
This annual festival is the occasion when the vel or trident, the weapon of Kathiresan, an aspect of the Hindu war-god Skanda, is borne in a gorgeous gilded chariot from the Kathiresan Kovil in Sea Street, Colombo 11 to a Kovil in Bambalapitiya or Wellawatta in alternation each year.
September
The annual vintage car rally is a popular event featuring an impressive line-up of over 125 “Old Crocks” ranging from the earliest cars to sports MGs and convertibles of yesteryear. The annual Kite Festival, held in the heart of Colombo by the sea, offers a spectacular kaleidoscope of airborne creations that are truly breath- taking.
October/November
Deepavali
Deepavali, the joyous Hindu Festival of Lights, is observed in late October or early November to celebrate the triumph of good over evil and to welcome Lakshmi, the goddess of wealth and fortune. It marks the beginning of the financial year for the Hindu business community. This "festival of lights" is observed to welcome Lakshmi the Godess of wealth and fortune into Hindu homes which are gaily lit up with oil lamps and lights. The festival is held at the end of October or at the beginning of November. Oil lamps are lit to denote the triumph of good over evil as it signifies the Indian god king Rama's return from Sri Lanka.
December
Christmas
Christmas is celebrated in Sri Lanka in true style, with all the traditional trappings, except snow, and is eagerly anticipated by those of all religions as a time of revelry. Indeed, the week leading up to the dawn of the New Year is one long extended period of goodwill and merry-making.
Sangamittha Perahara
The Sangamittha Perahara is also a colorful procession organized by Handala Rajamaha Viharaya in Handala in December. This procession is organized to commemorate the arrival of Ven Sanghamittha, daughter of Emperor Ashoka, to Sri Lanka with a branch of the Boo tree at which Lord Buddha attained to enlightenment.