Beyond high temperatures: understanding heat stress in Tamil Nadu
For Tamil Nadu, peak summer traditionally ends in May. But this season, temperatures hovering around 40 degrees Celsius in several districts extended the searing conditions
For Tamil Nadu, peak summer traditionally ends in May. But this season, temperatures hovering around 40 degrees Celsius in several districts extended the searing conditions well into June, leaving residents grappling with exhausting days and uncomfortable, warm nights. Clearly, the time has come to go beyond seasonal, templated responses. It is against this backdrop that the State has recently rolled out its Heat Action Plan 2026, introducing measures such as local heat vulnerability mapping, early warning systems, and targeted interventions for vulnerable communities. At the same time, meteorologists are closely monitoring the tropical Pacific for strengthening of El Nino, which could influence weather patterns, rainfall, and heat risks in the months ahead. From outdoor workers and children to the elderly in dense urban neighbourhoods, rising temperatures and heat stress are a true test of endurance for all. Spending most of his day navigating Chennai’s roads to complete deliveries, Selvam, a platform-based gig worker, says access to drinking water remains a challenge. “I am wary of drinking water from public kiosks so I carry a water bottle, but it gets over within an hour. I either request to refill it at places where I make deliveries or rely on buttermilk that residents and temples distribute,” he said. Meteorologists said May 2026 was significantly warmer than normal across many parts of Tamil Nadu and among the hotter recent Mays, with inland areas experiencing persistent heatwave-like conditions. The observations of the Regional Meteorological Centre (RMC) indicate Vellore recorded the season’s hottest temperature of 42.5 degrees Celsius on May 22, followed by Tiruttani and Meenambakkam in Chennai. With temperatures peaking above the 40-degree mark during May’s last fortnight, persistent heat spell resulted in moderate to severe heat-stress and increased discomfort across many districts. RMC officials observed that the hot weather was driven by strong pre-monsoon solar heating, dry continental air prevailing over interior parts, and the delay in widespread southwest monsoon activity. Urban heat island (UHI) effect further intensified temperatures in densely populated areas. Vulnerable interior districts While factors such as inland location, limited influence of sea breeze, and semi-arid conditions make north interior and central interior districts most vulnerable to heat stress, the coastal urban Chennai Metropolitan Area (CMA) faces a different heat-related challenge owing to high humidity and UHI effect. A temperature of 37 degrees Celsius with high humidity can be more stressful to the human body than 40 degrees Celsius under dry conditions. Other meteorological factors, including cloud cover, rising humidity and wind patterns, played a role in warm nights in coastal places. Pointing out that heatwave-like conditions have become more frequent, longer-lasting, and intense over the past decade in line with trends across India, V.R. Durai, Director, Regional Weather Forecasting Centre, RMC, says hot weather spells are becoming persistent with consecutive days of 40-degree-mark temperatures occurring often in interior districts such as Salem, Erode, Tiruchi, and Madurai.
The BriefWire