It's Raining by Gail Gibbons (2015)
Gail Gibbons puts her signature style to work as she looks at rain from a child's perspective: What is rain? Why is it necessary? Where does it come from? She takes the reader through different components of a storm, from the smallest raindrop to the loudest claps of thunder, and includes tips on how to stay safe and dry. With clear facts, simple definitions, and fascinating details, Gibbons's exploration of rain is the perfect choice for curious young readers.