The north-east monsoon establishes itself through November, so the offshore returns to the south and west and the run of breaks from Hikkaduwa to Mirissa starts working again after five months off. The east coast is finished until May.
It builds rather than arrives, and that shape is the thing to plan around. The first two weeks can still look like October and the last two like January. If your dates are movable inside the month, take the back half: the same coast, the same villages, and a monsoon that has settled rather than one still making up its mind.
Prices have not caught up with conditions, which is the argument for the month. The camps are reopening, the bay at Weligama holds a fraction of the boards it will carry at Christmas, and the sea is at 29°C. For a first week this is the best ratio of conditions to company in the whole year, and it costs less than February for the privilege. Getting there is easy in a way Arugam Bay never is: Weligama is two to two and a half hours from Colombo on the expressway, the shortest transfer of the five villages, and the coast train to Ahangama and Midigama runs beside the water for the last stretch.
Seven coasts are at their own peak in November, and the warm ones are Senegal at 27°C and the Canaries at 22. Sri Lanka is good rather than excellent and it is 29°C, which is the trade the month offers: two degrees of water and a season that is still assembling, for a coast nobody has arrived on yet.

