Visiting Costa Rica in January
This is one of the most crowded months of the year as the end of the year holiday crowds usually pour over into the first week of January. It is a nice time to visit though because it is the end of the rainy season and should be dry in most parts. It is important to realize that you might hit the dry season in one area and the rainy season in another.
The Costa Rican families are on summer break and January is a time when the locals enjoy visiting some of the same beautiful beaches as the tourist. A Costa Rica whitewater rafting adventure might be at low water level during this time of year which could be good if you don't want it too rough and are looking for a real scenic view of the rivers as most are running clear this time of year.