In which state of India does the monsoon arrive first ?

The correct answer is Kerala . Key Points The Southwest Monsoon typically arrives at the Malabar Coast of Kerala around June 1st , marking the official onset of the rainy season in India. The Indian Meteorological Department (IMD) declares the onset based on specific parameters, including rainfall recorded at 14 designated stations across Kerala and Lakshadweep , Westerly Wind depth, and Outgoing Longwave Radiation (OLR) values. This atmospheric phenomenon occurs due to the intense low-pressure system developed over the Tibetan Plateau and the Thar Desert , which draws moisture-laden winds from the Indian Ocean . Upon reaching the southern tip of the Indian peninsula, the monsoon current divides into two branches: the Arabian Sea Branch and the Bay of Bengal Branch . The Western Ghats play a crucial role in intercepting the Arabian Sea Branch , leading to heavy orographic rainfall in Kerala before the moisture moves further north and east. Additional Information Regional Arrival Timelines: West Bengal : The Bay of Bengal Branch of the monsoon usually reaches this region by the first or second week of June , entering through the Ganges Delta . Assam : The monsoon moves rapidly toward Northeast India , arriving in Assam and neighboring states around June 5th , deflected by the Himalayas and Arakan Mountains . Maharashtra : The Arabian Sea Branch progresses northward along the coast, typically reaching Mumbai by June 10th . Geographical Context: While Kerala is the first mainland state to receive the monsoon, the Andaman and Nicobar Islands actually experience the first monsoon showers even earlier, usually around May 15th to May 20th . The Retreating Monsoon or Northeast Monsoon begins its withdrawal from North India in September and brings significant rainfall to Tamil Nadu and Andhra Pradesh during October and November .