The best time to see them is from July until November when the Antarctica Humpbacks arrive.
The best place to see Humpback Whales in Costa Rica is along the Osa Peninsula, specifically the town of Uvita.
This is kind of ironic because Uvita is also home to this unique land feature that resembles a whale tale.
There are several companies in Uvita which offer whale watching tours. These tours often also include snorkeling and possible dolphin sightings as well.
This time of year also happens to be the rainiest time of year. It is goa good idea to pack rain gear.