Planning for the weather is a good way to make your trip to Isla de Coiba relaxing and enjoyable, especially when you're splurging. The hottest months are usually March and April with an average temp of 83°F, while the coldest months are January and December with an average of 80°F. The rainiest months in Isla de Coiba are August, May, July, and October, with each month seeing an average of 22 inches of rainfall.