One book I would highly recommend for the Weather Theme is Little Cloud by Eric Carle. In the book little cloud moves across the sky changing into shapes like sheep, airplane, shark, trees, rabbit, hat and a clown. At the end he joined all the other clouds and turned into one big cloud and rained.
This book offers some wonderful follow-up activities:
1. Discussion on what a cloud is and how rain is formed. Check the link below for more information:
Information on Clouds
2. Craft - children can make their own shape clouds. Some of the images in the book are simplistic enough for children to even copy them. This could later be made into a big book.
The link below gives you more ideas:
Preschool and Kindergarten Activities