Primer on Agrohydrometeorology is a foundational book that provides an introduction to the field of agrohydrometeorology, which examines the relationship between meteorological, hydrological, and agricultural processes. This book is an endeavor to bridge the gap between theory and practice, providing a comprehensive overview of agrohydrometeorological principles and their practical applications. The book contains rare but comprehensive and interdisciplinary contents contribute to promote understanding, enthusiasm and applications of scientific knowledge of agrohydrometeorology to address pressing challenges anticipated by planet earth. With strong advances in data analytics, remote sensing, and artificial intelligence, agrohydrometeorology offers innovative solutions to meet the twin challenges of feeding a growing global population and preserving the Earth's natural resources. It aims to serve as a resource for students, researchers, policymakers, and practitioners who seek to address the multifaceted challenges posed by changing weather patterns, erratic hydrological cycles, and their impacts on agriculture. The book is designed to serve as a primer, providing a concise and accessible introduction to the fundamental concepts and principles of agrohydrometeorology. The book will not only enrich the readers understanding of agrohydrometeorology but also encourage innovative thinking and action toward building sustainable and resilient agricultural systems.