Climate change has added an average of 30 extra days of harmful heat each year to India’s coffee-growing regions between 2021 and 2025, according to new analysis by Climate Central.
During this period, India recorded roughly 118 days annually with temperatures above 30°C the threshold at which coffee plants begin to suffer. Of those, about 30 days each year were directly attributable to climate change, based on modelling that compared today’s carbon-polluted world with a scenario without human-driven emissions.
India produces about 3.5% of the world’s coffee, much of it cultivated across the Western Ghats. The state-level impacts are stark. Kerala saw an annual average of 65 additional extreme-heat days linked to climate change. Tamil Nadu experienced 43 extra days, while Karnataka the country’s largest coffee producer recorded 32 additional harmful-heat days per year. Rising heat stress is also emerging in Tripura and Telangana.
Temperatures above 30°C reduce yields, weaken plants and compromise bean quality, especially for arabica, the more heat-sensitive of the two main varieties grown in India. Though robusta dominates Indian production, it too faces mounting stress under prolonged heat and erratic rainfall.
Farmers say the changes are no longer theoretical. In Karnataka Kodagu district, growers report longer heat spells, warmer nights and faster soil moisture loss. Blossoming patterns have turned irregular, harvest cycles are disrupted, and in some cases, coffee cherries are drying prematurely on the plant.
The trend mirrors a broader global shift. Climate Central’s review of 25 major coffee-producing nations accounting for 97% of global output found that every country experienced additional coffee-harming heat days due to climate change. On average, producers saw 47 extra harmful-heat days annually, with the top five growers Brazil, Vietnam, Colombia, Indonesia and Ethiopia averaging 57 additional days per year.
Scientists warn that rising temperatures, shifting rainfall and shrinking suitable land could fundamentally reshape where and how coffee is grown in the coming decades. For India’s coffee belt, the warming is already rewriting the rules.