Thu Apr 17 00:49:00 UTC 2025: ## Bengaluru’s Scorching Summer: Urban Heat Island Effect Reaches Record Levels

**Bengaluru, April 17, 2025** – Bengaluru is experiencing a record-breaking heatwave, intensified by a worsening Urban Heat Island (UHI) effect. The city’s hottest day this year, March 14th (35.4°C), is likely just a precursor to even higher temperatures this month. Last year’s April high of 38.5°C was only slightly below the all-time April record of 39.2°C (April 25, 2016).

Experts attribute the intensified heat to the city’s dramatic loss of green cover, coupled with a rise in heat-absorbing infrastructure like white-topped roads, glass-façade buildings, and concrete structures. The UHI effect traps heat, with temperatures in affected areas potentially 3-5 degrees higher than surrounding areas. The depletion of trees and water bodies has exacerbated this problem.

The ongoing Namma Metro Phase 3 project is further contributing to the issue, with plans to fell 11,137 trees. Environmentalist Dattatreya Devare criticized the lack of transparency regarding the tree locations and the slow pace of compensatory plantation, highlighting delays in reporting to the court. While authorities cite a lack of space for replanting, Devare advocates for utilizing roadsides and secured a commitment from the BBMP to plant 50,000 saplings in 2025-26 for this purpose.

Research from the Indian Institute of Science (IISc) reveals a stark decline in Bengaluru’s porous landscape (vegetation and water bodies) from 68.2% in 1973 to a mere 6.02% in 2025. Conversely, paved surfaces have increased from 7.97% to 87.64%. This has resulted in decreased groundwater recharge and a significant temperature rise, from approximately 19°C in the 1990s to 36-38°C today, according to Dr. T.V. Ramachandra from IISc. He points to the successful rejuvenation of Sarakki Lake, which saw a 300ft improvement in groundwater levels within a year, as a positive example.

The IISc study also highlights the increased electricity consumption of glass-façade buildings, contributing to global warming and further increasing temperatures. These elevated temperatures pose significant health risks, including heat stroke, respiratory problems, and heat-related mortality, particularly for vulnerable populations.

Experts emphasize the need for a holistic approach to urban green infrastructure, including interlinking green patches, regular tree maintenance, and incorporating vertical green cover on buildings. The Karnataka State Heat Wave Action Plan 2023-24 provides a framework for mitigation measures, but its effective implementation is crucial to combating the escalating UHI effect and mitigating its health consequences.

Read More