Climate of Northeast India: Characteristics, Types, Rainfall and Temperature Northeast India has a predominantly tropical character, particularly in its valley regions. The region experiences a monsoon climate characterized by heavy to very heavy rainfall, concentrated mainly during the four summer months from June to September. The southwest monsoon is the principal source of rainfall, and June is generally the rainiest month. The climate of Northeast India is strongly influenced by its geographical location, varied topography, altitude, mountain ranges, river valleys and the southwest monsoon. As a result, considerable climatic variations can be observed between the plains, valleys, foothills and high mountain areas. Climate Characteristics of Northeast India Northeast India generally experiences three major seasons—winter, summer and rainy season . As in much of India, the rainy season largely coincides with the summer months because of the influence of the southwest monsoon. A ma...