Climate change added an average of 30 extra days of harmful heat annually to India’s coffee-growing regions between 2021 and 2025, according to new data from Climate Central, an independent group of scientists and communicators who research and report on climate change and its impacts.
India recorded about 118 days per year (between 2021 and 2025) above 30°C, the temperature threshold beyond which the heat harms the coffee plants. Roughly 30 of those days were driven by climate change, the analysis shows. It arrived at this by modelling the number of days each year that would have recorded maximum temperatures below 30°C in a world without carbon pollution but were pushed over the threshold due to carbon pollution, representing the coffee-harming days attributable to climate change.
India accounts for 3.5% of global coffee production. State-level data highlights the impacts in key coffee regions of the country. Kerala experienced an annual average of 65 additional extreme-heat days linked to climate change. Tamil Nadu saw 43 extra days each year, while Karnataka, India’s largest coffee-producing state, recorded 32 additional harmful-heat days annually. Parts of the northeast also showed rising heat stress, with Tripura recording 47 extra days and Telangana 44.
Temperatures above 30°C reduce yields, affect bean quality and increase plant stress, particularly for arabica coffee, which is more heat-sensitive than robusta. India grows both varieties, though primarily robusta, largely across the Western Ghats.
Farmers say these changes are already visible. Sohan Shetty, who manages biodiversity-rich shaded organic coffee farms in the Western Ghats, said, “We are seeing two significant changes: increased temperatures and erratic rainfall. We see a reduction in soil moisture, even in shade grown coffee. This creates stress for coffee plants, which in turn triggers blossoms with erratic rains. So, it’s quite common to see planters halting harvesting because a part of their plants has blossomed. We have had our coffee fruit drying up in the plants faster because of increased temperatures.”
In Kodagu, Karnataka, growers are tracking the shifts closely. Akshay Dashrath, Co-Founder and Grower at the South India Coffee Company, said, “At Mooleh Manay, our farm, climate change isn’t something we’re predicting, it’s something we’re measuring every day. Our on-ground sensors show longer stretches of high daytime temperatures, warmer nights, and faster soil moisture loss than what coffee here has historically depended on.”
The India findings reflect a broader global pattern. Climate Central analysed temperature data from 2021 to 2025 across 25 major coffee-producing countries, which together account for 97% of global production. All 25 experienced additional days of coffee-harming heat because of climate change. On average, countries saw about 47 extra harmful-heat days annually. The top five producers — Brazil, Vietnam, Colombia, Indonesia and Ethiopia — experienced an average of 57 additional harmful-heat days per year.
Researchers warn that rising heat, shifting rainfall and shrinking suitable land could reshape coffee cultivation in the coming decades.
Banner image: Coffee plant in Tamil Nadu. Image by Mirthyu via Wikimedia Commons (CC BY-SA 4.0).
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