When we left the hotel in Chennai to get to the airport at 5 am with Uber, there was incredible smog, visibility of one meter at most. The driver told us that it was because of the celebration of Pongal. Pongal is a harvest festival dedicated to the Sun. It is a four-day festival which is usually celebrated by Tamil Nadu from 14 January to 17 January. The day preceding Pongal is called Bhogi. On this day people discard old belongings and worn-out items and celebrate new possessions. The people assemble at dawn to light a bonfire in order to burn the discards, setting bonfires on the streets with agricultural and household waste. We were told that people burn anything they can find in the streets and it causes so much smog. Our flight and all other flights were delayed by five hours because of the smog.