Maha Shivaratri is the main festival which is celebrated in the temple. Cultural and musical programmes are held in the temple premises. many thousands of oil lamps are lighted at the festival. The idol of Wadakkunathan is not taken out for any procession even on Shivarathriday. Maha Shivaratri is celebrated on the “Krishna Paksha Chaturdashi” of hindu calendar month “Maagha” as per “Amavasya-ant” month calculation. As per “Poornima-ant” month calculation, the day is “Krishna Paksha Chaturdashi” of Hindu calendar month Phalguna which falls in February or March as per the Gregorian calendar
The Thrissur Pooram, celebrated in the Malayalam month Of Medom (April-May) is a grand assembly of Gods and Goddesses in and around Thrissur. These Gods and Goddesses make their visit to the Wadakkunathan Temple premises on caparisoned elephants accompanied by grand ensembles of “Chenda melam” and “Pancha Vadyam”. There is no special pooja or special offering during the pooram day to Lord Vadakkunathan. The Lord who is the presiding deity of the town, remains a happy and silent felicitator of pooram. All the ten deities celebrating pooram, together with LordSiva of Asokeswaram reach Vadakkunnathan temple on the Sivarathry day.
The Aanayoottu of feeding of elephants, is the second biggest festival held in the temple. The devotees refer to elephants as Lord Ganesh's incarnation. The festival falls on the first day of the month of “Karkkidakam”, which coincides with the month of July. It has been the regular annual practice at the temple for the last many years to conduct a large-scale “Ashta Dravya Maha Ganapathy” Havana and “Aanayoottu” on the first day of the “Karkkidakam” month of the Malayalam calendar. It involves a number of unadorned elephants being positioned amid a multitude of people for being worshipped and fed. A large number of people throng the temple to feed the elephants. “Gajapooja” is conducted once every four years.
Thiruvathirai festival is observed on the Tiruvathira Nakshatram day in the Malayalam month of Dhanu Masam (December – January).The festival is mainly dedicated to Lord Shiva and there are two popular beliefs – one is that on the day Kamadeva was burned to ashes by Lord Shiva. Another legend is Lord Shiva’s return to the world after ending harsh austerities and tapas that he was performing after the death of Goddess Sati
