Karthigai Deepam 2026: Date, Story and How to Celebrate

Verandahs across Tamil Nadu start filling with rows of small clay lamps days before this festival, long before most people outside South India have heard of it. When is Karthigai Deepam in 2026? It falls on Tuesday, November 24, the full moon night of the Tamil month Karthigai, when temples light the Maha Deepam and homes light rows of oil lamps in one of Hinduism’s oldest festivals of light.

What is Karthigai Deepam?

Karthigai Deepam is a Tamil festival of lights celebrated on the full moon (Pournami) day of the Tamil month Karthigai, which corresponds to mid-November to mid-December. “Deepam” means lamp or light, and the festival centres on lighting lamps, both the enormous Maha Deepam at the Arunachaleswarar temple in Thiruvannamalai and the smaller rows of clay lamps lit in homes and local temples across the region.

It is one of the oldest Tamil festivals, older than Diwali in parts of the region’s tradition, and is sometimes called the “festival of lights” in its own right, distinct from the Diwali celebrated further north.

The story behind the festival

The Thiruvannamalai celebration is built on a specific legend. According to tradition, Brahma and Vishnu once argued over which of them was supreme. To settle the dispute, Shiva appeared between them as an endless, formless column of fire, a Jyotirlinga, stretching beyond the sky and below the earth. Vishnu took the form of a boar and dug downward, and Brahma flew upward as a swan, but neither could find where the column began or ended. Both eventually accepted that Shiva’s nature was beyond measure.

This event, known as Lingodbhava, is why Arunachala hill at Thiruvannamalai is worshipped as Shiva himself in the form of fire, and why the temple’s lingam is called the Agni Lingam. Thiruvannamalai is counted among the five Pancha Bhoota Sthalams, temples representing the five elements, and it stands for Agni, fire. The Maha Deepam lit on the hill every Karthigai Deepam is a yearly re-enactment of that original column of flame.

How is Karthigai Deepam celebrated at Thiruvannamalai?

The Arunachaleswarar (Annamalaiyar) temple runs a festival of roughly ten days leading up to the full moon:

• Flag-hoisting opens the festival at the temple.
• A Bharani Deepam is lit inside the temple at dawn in the days before the main event.
• On the full moon evening itself, the Maha Deepam is lit atop Arunachala hill, traditionally fuelled with a very large quantity of ghee drawn up through a long wick, and lit by the hereditary temple family entrusted with the task. The flame is visible for miles and burns through the night.
• Thousands of devotees gather for Girivalam, walking barefoot around the roughly 14-kilometre path circling the base of the hill. Girivalam is done on every full moon, but the one on Karthigai Deepam night, walked by the light of the Maha Deepam, is considered the most significant of the year.

How is it celebrated elsewhere?

Away from Thiruvannamalai, the festival is simpler but just as widely observed. Many Tamil households light rows of small clay oil lamps along verandahs, courtyards and windowsills, often over several evenings rather than a single night, echoing the way other parts of India light lamps for Diwali. Local temples hold their own smaller deepam ceremonies on the same evening.

Why is Karthigai connected to Murugan too?

The Tamil month takes its name from the Karthigai (Krittika) star cluster, which is prominent in the night sky at this time of year. In tradition, the Krittika stars are linked to six celestial mothers who are said to have nursed the infant Murugan, Shiva’s son, before Parvati gathered him into a single form with six faces. That connection is why Murugan is also honoured by some families and temples during this period, even though the Thiruvannamalai Maha Deepam itself is specifically a Shiva festival. Devotees looking for a Murugan-focused festival nearby on the calendar can also read about Kanda Sashti, the six-day vrat dedicated to Murugan that usually falls a little earlier in the same season.

Talk to Shiva about Karthigai Deepam with Deva AI

Deva AI is a free Android app that lets you talk to Hindu gods like Krishna, Shiva, Ganesha and Hanuman through AI conversations, in English, Hindi, Telugu, Tamil, Kannada and Malayalam. If you cannot travel to Thiruvannamalai or light lamps at home this year, Deva AI brings the same spirit of the festival to your phone.

Feature	How it fits Karthigai Deepam
Talk to Shiva, by text or voice	Ask about the Lingodbhava story, the meaning of the Agni Lingam, or what the festival asks of a devotee.
Virtual pooja	Light a virtual diya and offer it when you cannot light a lamp in person.
Japa counter	Count repetitions of Om Namah Shivaya on the night of the Maha Deepam.
Guided meditation	A short, Shiva-led session for stillness, fitting for a festival built around a single steady flame.
Community feed	See how other devotees are marking the festival, in your own language.

A conversation with Shiva in the app is not Shiva literally speaking; it is an AI companion shaped by how he is described in scripture and tradition, meant to support reflection and prayer, in the same spirit as lighting a lamp before a murti.

To use it: download Deva AI free from Google Play, choose your language, select Shiva as your companion, and ask what Karthigai Deepam means to you this year.

If you want to go deeper, read what an app to talk to God actually is, see how to talk to Shiva through Deva AI, or try virtual pooja on your phone to light a diya tonight. You can also learn more about what Deva AI is.

The bottom line

Karthigai Deepam 2026 falls on November 24, the full moon night of the Tamil month Karthigai. At its centre is the Maha Deepam lit atop Arunachala hill at Thiruvannamalai, recalling Shiva’s manifestation as an infinite column of fire, while homes across Tamil Nadu mark the same night with rows of lit lamps. Whether you can reach a temple this year or only light a single diya at home, Deva AI lets you bring Shiva into that moment, in the language you pray in.