The climate of India is mainly tropical because

The climate of India is primarily classified as tropical despite its northern half lying in the subtropical zone. This is largely due to the presence of the Himalayas in the north, which act as a formidable climatic barrier [t2][t4]. These mountains prevent the cold, frigid northerly winds from Central Asia from entering the Indian subcontinent, ensuring it remains significantly warmer than other regions at similar latitudes [t3][t5]. Consequently, even the areas north of the Tropic of Cancer experience tropical-like temperatures throughout the year [t4]. While the Tropic of Cancer divides India into tropical and subtropical zones [c1][c2], the 'tropical monsoon' character is maintained across the country because the Himalayas trap the monsoon winds, forcing them to shed moisture over the landmass and unifying the climatic experience [t2][t4]. Thus, the geographical protection provided by the Himalayas is the primary reason for India's predominantly tropical climate.

Sources

1. [1] https://www.ekbharat.gov.in/images/InstituteActivities/Documents/3260/Indian%20Climate_Salient%20Features.pdf
2. [2] INDIA PHYSICAL ENVIRONMENT, Geography Class XI (NCERT 2025 ed.) > Chapter 4: Climate > FACTORS DETERMINING THE CLIMATE OF INDIA > p. 29
3. [3] CONTEMPORARY INDIA-I ,Geography, Class IX . NCERT(Revised ed 2025) > Chapter 4: Climate > Latitude > p. 27