January is the middle of the dry season on the Pacific coast. The Southern Hemisphere swell that ran from April to October has stopped, so what arrives is smaller and comes mostly from the north. The north-east trades make up for it: they blow offshore across the Nicoya peninsula almost daily, and a small wave held open by wind beats a bigger one falling over itself.
Tamarindo, Playa Grande and Nosara are the names that come up for exactly this reason: one of the good months of the year, without being the best. It is also the driest stretch of the year and the busiest, since the weather brings everybody else too. The water is at 28°C and boardshorts are the whole kit.
