Most of the information you read will tell you that Panama has two seasons.  The dry season from January to April and the wet season from April to December.  This is true of the Pacific coast and some other parts of Panama, but not necessarily of Bocas del Toro which is on the Caribbean Ocean.

The weather in Bocas is different. This is the tropics so rain can come at any time, but the two "dry seasons" of Bocas are February through May and September through October.   September can usually be depended upon to give us the calmest sea conditions and the most sunny days, while July and December usually have the most rainy days.