Hyderabad: It is July. Rain clouds have returned, but the heat has not left Hyderabad. Between humid afternoons and intermittent showers, residents continue to grapple with uncomfortable temperatures, while the India Meteorological Department warns that above-normal heat is likely to persist.
Industrial growth to blame
And now, a study published in Scientific Reports has traced a significant part of the blame to something that has expanded relentlessly across Telangana for two decades: industrial growth.
Researchers from the Singapore Institute of Technology, Vignanan Bharathi Institute of Technology and other institutions spent two years analysing satellite data, land-use records and meteorological observations across Telangana between 2003 and 2023.
What they found reframes how the state must think about the heat that now defines its summers.
Industrial expansion, they concluded, has become a primary driver of rising temperatures across Telangana’s cities, pushing heat far beyond what background climate change alone would produce.
The numbers behind the heat
The study tracks what researchers call the Urban Heat Index, a measure of how much hotter urban and industrial areas run compared to surrounding non-urban zones.
In 2003, the average Urban Heat Index in Telangana’s industrial areas stood at 1.35. By 2023, it had nearly doubled to 2.70. Non-industrial areas also warmed over the same period, but at a considerably slower pace, rising from 1.00 to 1.82.
Comparing surface temperatures
The difference in land surface temperatures tells an even starker story.
Industrial zones recorded surface temperatures of 33.8°C in 2003. By 2023, that figure had climbed to 39.8°C, a rise of six full degrees in two decades. Non-industrial areas, by comparison, recorded an increase from 31.4°C to 35.9°C for the same period.
The researchers used machine learning models to identify which factors drive these changes most powerfully. Industrial land use, built-up density and near-surface air temperature emerged as the dominant contributors. The models achieved a predictive accuracy of R² ≈ 0.87, a level that gives the findings considerable statistical weight.
“Industrial land use, built-up density, and near-surface air temperature are the dominant predictors of UHI variability, while vegetation cover plays a moderating role,” the authors noted.
Industry versus climate change
Perhaps the most arresting finding in the study sits in a single comparison.
Over the entire 20-year study period, background pre-monsoon air temperatures across Telangana rose by approximately 0.6°C. That figure represents the contribution of broader climate warming to the region’s heat.
Industrial zones, over the same period, recorded surface temperature increases of 6°C.
The heat building inside Telangana’s industrial corridors is therefore running at roughly 10 times the pace of background climate warming. The study makes clear that this is not a coincidence of geography. It is a consequence of how industrial land functions.
What happens when too many industries come?
Factories, warehouses, processing plants and the infrastructure around them cover the ground in impervious surfaces. Vegetation disappears. Buildings pack together. Roads and rooftops absorb solar radiation through the day and release it slowly through the night, denying surrounding areas the temperature drop that undeveloped land would allow.
“Industrial zones are characterised by extensive impervious surfaces, dense infrastructure and reduced vegetation cover, all of which increase the absorption and retention of solar radiation,” the authors noted. “Industrial-driven heat amplification exceeded the impact of background climatic warming.”
Where does the heat concentrate?
The study maps Telangana’s heat across time, identifying corridors and cities where industrial growth has produced the steepest thermal intensification.
Three zones emerge as the state’s most persistent hotspots: the Hyderabad-Medak region, the Rangareddy-Sangareddy belt and the industrial zones around Warangal.
These areas have consistently recorded the highest surface temperatures in the state, running substantially hotter than surrounding agricultural and vegetated land.
Significant increase in hotspots
The total area across Telangana classified as statistically significant heat hotspots grew from roughly 1,100 sq km in 2003 to approximately 2,100 sq km in 2023. Industrial regions drove nearly 70 per cent of that expansion. Their share of total hotspot area climbed from 38.2 per cent in 2003 to 53.3 per cent in 2023, meaning industry now accounts for more than half of all extreme heat territory across the state.
The spatial analysis also found that higher Urban Heat Index values cluster directly around industrial estates, with heat intensity falling as distance from industrial zones increases. Built-up density reinforces the effect, while proximity to vegetation and water bodies pulls temperatures down.
Warangal: A city that doubled its heat
The study dedicates a focused analysis to Warangal, examining the city as a representative case of what industrial expansion does to a secondary urban centre over time.
The findings are unambiguous. Warangal’s mean Urban Heat Index doubled from 1.2 in 2003 to 2.4 in 2023. The area of the city covered by statistically significant heat hotspots expanded by approximately 62 per cent over the same period.
Researchers attribute much of this intensification to industrial corridor expansion in the city’s northeastern sector, where new estates have replaced open land, stripped out tree cover and added large volumes of impervious surface.
“Statistically significant hotspot area increased by approximately 62 per cent, confirming the localised thermal amplification associated with industrial growth,” the authors noted. The rate of change in Warangal tracks closely with state-level trends, which the researchers say confirms that the industrial heat dynamic operates consistently across both large and secondary cities.
The gap between surface and policy
The study does not stop at documenting the problem. It argues directly that heat mitigation strategies must now be built into the architecture of industrial and urban planning in Telangana, rather than treated as an afterthought.
Researchers estimate that increasing green buffer coverage around industrial areas by just 10 per cent could reduce the Urban Heat Index by approximately 0.15 units. That figure comes from an analysis of the relationship between vegetation indices and heat intensity observed across the study period.
Other interventions the authors point to include reflective roofing on industrial buildings, which reduces the amount of solar radiation absorbed and re-emitted, and revisions to industrial zoning policies that would require heat considerations to factor into approvals for new estates.
“Targeted interventions such as industrial green buffers, reflective roofing and integrating heat considerations into industrial zoning policies could help mitigate future heat risks,” the authors noted.
How the heat spreads
The study also flags a proximity problem that planners have so far largely ignored.
Industrial estates in Telangana sit close to expanding residential areas, meaning the heat they generate does not stay contained within estate boundaries. It spreads into the neighbourhoods where workers and families live.
“The spatial proximity of industrial estates to expanding residential areas further exacerbates heat exposure, underscoring the importance of considering urban-industrial interactions in heat mitigation strategies,” the authors noted.
A heat signal that will not fade
For Hyderabad’s residents, three months of relentless heat already feels like evidence enough that something has changed. The study now provides the data behind that feeling.
Telangana has built itself into one of India’s most industrially active states over the past two decades. Pharmaceutical clusters, bulk drug manufacturing, food processing and technology infrastructure have transformed land across the Deccan Plateau. That transformation has delivered economic growth.
It has also, the researchers demonstrate, delivered heat on a scale that climate change alone does not explain.
“Industrial development has become a major factor shaping Telangana’s urban thermal environment," the authors noted. “Heat mitigation strategies must be incorporated into future industrial and urban planning to improve climate resilience and public health outcomes.”
What happens next March?
The monsoon will arrive eventually, and temperatures will fall. But the industrial corridors will remain, and next March, the heat will return. The study makes the case that without deliberate intervention, it will return stronger.
