December is the dry season settling in. The north-east trades are back to blowing offshore across the Nicoya most mornings, the rain has gone, and the swell has dropped to what a north Pacific winter sends this far south, which is not much. What it is worth, it owes to shape rather than size.
It is also the month the Caribbean coast wakes up. Puerto Viejo and Salsa Brava run from December to March on a completely different weather system, so a December trip can be two trips. The water is at 28°C on the Pacific. The islands fill from about the twentieth and stay full into January.
