Understanding India's Rainfall

The Indian subcontinent encounters distinct rainfall patterns, primarily driven by the southwest monsoon and northeast monsoon. From June to September, the southwest monsoon, commonly referred to as the 'long rains,' contributes approximately 75% of India's annual rainfall, while the northeast monsoon, known as the 'short rains,' accounts for the remaining 25% and occurs from October to December. The Southwest Monsoon is the primary source of rainfall in India. This seasonal rainfall is crucial for crop growth, initiated by a low-pressure area forming over the Bay of Bengal. India experiences varied rainfall distribution across its regions, with the western coast receiving the highest precipitation. In contrast, the eastern coast witnesses comparatively lower rainfall. The northeastern states, such as Assam and Meghalaya, emerge as the wettest regions, with annual rainfall exceeding 2000 mm. The distribution of rainfall across India shows diversity, with the average annual rainfall ranging from about 50 inches (1270 mm) in the western Himalayan region to around 160 inches (4000 mm) in the northeastern part of the country. Distinct regions in India experience different levels of precipitation, from less than 50cm in the desert and semi-arid regions of Rajasthan or Gujarat, to over 100cm in the coastal regions of South India and inland areas, to over 200cm in the north-east, with some areas having even over 400cm in places like Assam and Meghalaya. India exhibits diverse weather conditions, showcasing varying rainfall patterns across regions and seasons. Monsoons dominate the south, while the Himalayan region experiences heavy snowfall. This overview aims to provide insights into the distinctive rainfall types experienced throughout India during the year.

India experience more rainfall on average in comparison to the rest of the world, receiving receiving broadly between 1000-2000 mm of rainfall per square meter in most of the country. Its positioning between major water bodies as well as its proximity to the equator plays a large role in facilitating this.

With the onset of climate change, there have been some changes in India's rainfall patterns. While the average rainfall in central and coastal areas has risen, it has fallen in the north east and extreme rainfall areas.

The total amount of rainfall in the country has risen, but it has not risen equitably. This can be seen in the chart below, with largely extreme changes in rain patterns visible in most states.

The rise in rainfall can also be linked to increasing water related disasters. The adjacent chart illustrates the number of rainfall-related floods in India between 2013-2016, demonstrating the need for India to start learning how to cope with these varying climactic conditions. Hence, through this storymap a glimpse into India's rainfall condition has been made, as well as the trajectory it is currently on.