Ganesh Chaturthi marks the birth of Ganesha, the remover of obstacles. It begins on the fourth tithi of the bright half of Bhadrapada and, in its most visible form, runs for ten days until Anant Chaturdashi, when the idols are immersed. In 2026 it begins on Monday 14 September.
Maharashtra is the festival's centre of gravity. Households install a clay Ganpati for one and a half, five, seven or ten days; neighbourhood mandals install large idols in decorated pandals with daily aarti, prasad and cultural programmes. Public celebration in this form goes back to Bal Gangadhar Tilak's Sarvajanik Ganeshotsav in the 1890s, which deliberately built it into a community festival.
In Tamil Nadu the same day is Vinayaka Chaturthi, with a home puja and kolukattai as the offering. In Karnataka and Andhra the celebration is largely domestic. In Goa it is Chavath, with a distinct set of rituals.
The festival's most important modern argument is environmental. Clay idols dissolve within hours; plaster of Paris idols, painted with lead and mercury pigments, do not, and their immersion is the single largest source of heavy metal pollution in Mumbai's water bodies each year. Most municipal corporations now require clay idols and have designated artificial immersion tanks.