The Indian summer monsoon, also known as the southwest monsoon, falls within the South Asian monsoon and is the strongest and perhaps best-known of the world’s monsoons. During summer months when the Asian landmass heats up, warm, moist air flows northward from the Indian Ocean towards the Himalayas, bringing abundant showers and thundershowers to India. The summer monsoon is a regular event that occurs every year and is responsible for roughly 80% of India’s annual rainfall. The summer monsoon typically starts in early June, peaks in July and August and winds down during September and early