Tamil Nadu hill stations warming up due to construction surge and forest decline

CHENNAI: The holiday-favourite hill regions across Tamil Nadu are warming up, and it is linked to increasing construction and declining green cover, particularly in terrain blocks under pressure from tourism and development.

The Decadal Assessment of Urban Growth and Thermal Stress in Tamil Nadu (2025), released by the State Planning Commission, finds that several high-altitude regions like Kodaikanal, The Nilgiris, and parts of the Palani and Western Ghat foothills have seen a steady rise in surface temperatures over the last three decades.

The report points out the expanding construction and shrinking green cover as key reasons, especially in terrain blocks under tourism and development pressure.

One of the major concerns flagged is the loss of forests. Tamil Nadu has lost over 3,025 sq. km of forest since 2000, according to the India State of Forest Report 2023. While this figure is statewide, the assessment highlights that hilly areas have experienced forest loss alongside real estate growth, especially along sensitive slopes and fringes.

Kodaikanal block in Dindigul district is explicitly identified in the report as showing surface warming linked to land-use change.

An earlier, peer-reviewed remote sensing study (1969–2008) found that Kodaikanal's built-up area increased from 3 per cent to 21 per cent, while forest cover declined from 70 per cent to 33 per cent during that period. The state report’s findings, covering 1985-2015, suggest that this trend has continued into more recent years. "Urban expansion into fragile hill slopes and forest fringes… coincides with notable increases in temperature," the report states.

The study classifies 90 terrain blocks across the state, areas located above 330 metres in elevation. Among these, it finds that places like The Nilgiris, Theni, and Erode are showing signs of rising surface heat and loss of tree cover. While exact temperature figures were not published for each block, the pattern is consistent where forests have been cleared and buildings have gone up, heat has increased.

Tamil Nadu has frameworks like the State Climate Change Mission and SAPCC 2.0 in place. But, the report flags that most policies focus on cities and plains, and not the hills. "Integration of thermal indicators into local planning remains a critical gap," it notes.

How to keep it chill

Enforce land use regulations near forest slopes

Restore native vegetation in hill zones

Use thermal maps to guide new construction, especially in tourism areas

Set up block-level systems to monitor heat trends in terrain areas