Azim Premji Study Projects Sharply Divergent Monsoon Shifts Across India's Coast

A new study by Azim Premji University projects that coastal districts in Gujarat and Maharashtra will receive considerably higher southwest monsoon rainfall by 2040, while coastal Odisha and West Bengal, including the Sundarbans, face reduced monsoon precipitation. Approximately 40 coastal districts across India are likely to see maximum summer average temperatures rise by over 1 degree Celsius above the 1960s baseline, with the west coast facing the greatest heat stress.

The study, Indian Coastal Region: Climate Projections 2021-2040, uses CMIP6 model projections corrected for regional bias at a granular 25 by 25 kilometre scale. Kachchh in Gujarat is projected to receive 31 per cent higher average rainfall in the southwest monsoon season compared to its historical level of 322 millimetres precipitation. Jamnagar and Devbhumi Dwarka districts are each expected to see 28 per cent higher rainfall. Ahmedabad is projected to receive 44 per cent higher northeast monsoon rainfall, and Mumbai City district a 32.7 per cent rise. In contrast, the northeast monsoon will bring excess rain to coastal Maharashtra and Gujarat in a pattern that deviates from historical norms.

Ernakulam district in Kerala is projected to experience the maximum rise in maximum summer average temperature, at plus 1.3 degrees Celsius, followed by Alappuzha and Kozhikode at plus 1.2 degrees Celsius. The study warns that coastal Kerala and Tamil Nadu are likely to experience high summer wet-bulb temperatures touching 31 degrees Celsius, considered the threshold at which dangerous heat stress begins for healthy resting individuals. Wet-bulb temperature accounts for both air temperature and humidity; in humid conditions, reduced evaporative cooling makes the human body feel substantially hotter than dry bulb readings suggest. On the east coast, Tirunelveli in Tamil Nadu and Khorda in Odisha face a maximum summer temperature rise of 1.1 degrees Celsius.

The study was presented at a launch event in Mumbai on May 29, 2026. Azim Premji Foundation CEO Anurag Behar said 2040 is only 16 years away and that the dataset highlights the need to restructure infrastructure and governance urgently. Harini Nagendra, Director of the School of Climate Change and Sustainability at Azim Premji University, said the findings make clear that India's climate crisis is hyper-local and immediate, affecting heat stress in Ernakulam and rising salinity in the Sundarbans in ways already visible in daily life. The study argues for climate resilience strategies built on precise, district-level projections rather than broad national averages, enabling targeted adaptation by local governments and infrastructure planners.

Key figure — 31% higher monsoon rainfall projected for Kachchh by 2040