The second sound of Rainy Season in Southwest Florida, is a result of the rain, and it is the peeping trill of thousands of frogs. Once the rain comes (and the temperature warms up) the frogs start to sing. Not every area sounds the same. I am sure that different areas have different types of frogs which causes a variation in the sounds of the chorus. And, maybe things like the size of the body of water, and the time of day, are factors in the different sounds.