November to February is the best time to visit Goa, and within that window there is a further choice to make.
Mid-November to mid-December is arguably the sweet spot — the weather is fully settled, the sea is calm, shacks are all open, and the extreme peak-season crowds and prices have not yet arrived.
Mid-December to early January is the absolute peak. Christmas and New Year in Goa are a major event, the state is at its liveliest, and there is a real festival atmosphere — but accommodation prices can triple or more, beaches and roads are packed, and booking months ahead is essential. Come for this if the atmosphere is the point; avoid it if you want space.
January to February remains excellent — the weather is still ideal, crowds thin out after the New Year rush, and prices settle. For many people this is the best combination of conditions and value.
October and March are shoulder months. October sees the state reopening after the monsoon, with green landscapes and low prices but incomplete infrastructure early in the month. March is still comfortable and considerably cheaper than peak, with warm sea temperatures.
April and May are hot and humid but cheap and quiet, with the sea still swimmable. Reasonable if you prioritise price and space over comfort.
June to September is for a specific kind of traveller — someone who wants green, empty, dramatic Goa and doesn't mind that swimming is off the table and most shacks are gone. Prices are at their lowest. The Western Ghats and waterfalls are the draw rather than the beach.
Festival timing: the Goa Carnival falls in February or March, Shigmo (the Goan spring festival) in March, and the Feast of St. Francis Xavier on 3 December.