Which days are busiest

Crowds build from Chaturthi, jump on Shashthi, jump again on Saptami evening, and peak on Ashtami night. Navami is very close behind. Dashami is different in kind — the crowd moves to the ghats.

Within a day the curve runs from near-empty at seven in the morning to peak between eight and eleven at night, then falls away after midnight.

The one thing that changes this is rain, which empties the streets within twenty minutes and refills them within an hour of stopping.

Shift the day. Chaturthi and Panchami give you finished pandals and a fraction of the crowd. This is what a lot of Kolkata actually does, and it is why the city's own pandal hopping starts before the festival officially does.

Shift the hour. If you must go on Ashtami, go at seven in the morning or after one at night. Both give you the same pandals without the queue.

Around a small number of very well-known pujas, and along the roads leading to them — which is why a neighbourhood two kilometres from a famous puja can feel completely different from one two hundred metres away.

Block-organised areas such as Salt Lake, Lake Town and Dum Dum Park are, as a rule, the most walkable on a peak night, because their pujas are spread across residential blocks rather than concentrated on one ground.

This site publishes no crowd forecast for any individual puja. What it does have is community crowd reports on each puja's own page — people saying what it is like right now — and that is a much better guide than any prediction.