Weather is probably a major factor when you plan your trip to Bioko Island, but bear in mind that cheaper options are usually available when the weather isn’t as good. The hottest months are usually March and April, with an average temperature of 27°C, while the coldest months are August and July, with an average of 25°C. The rainiest months in Bioko Island are August, June, July and September, with each month seeing an average of 762 mm of rainfall.