Complex sentence: June-October is the areas monsoon/rainy season, while in December-May there are "trade winds" which bring little rainfall, making it harder for the frog to find suitably wet places to breed.
Split into simpler sentences: June-October is the areas monsoon/rainy season, while December-May there is little to no monsoons. During this season there are "trade winds" which bring little water making harder for the frog to find sutible places to breed.