For years, 37.7°C recorded on March 16, 1988, remained the highest March temperature in Thiruvananthapuram, a number that belonged to another time, another kind of summer.
This year, it has been overtaken.
On Sunday, the city recorded 37.8°C, the highest ever for March, breaking a record that had been held for nearly four decades.
The heat has been building since February, with afternoons turning increasingly difficult to get through.
Even as parts of Kerala receive scattered summer showers, the capital has seen little relief. The occasional rain has barely dented the daytime temperatures, which quickly climb back up under clear skies.
What makes it worse is the lack of respite at night. With temperatures hovering around 25°C after sunset, the city is not cooling down enough, leaving many feeling drained even before the next day begins.
‘Getting unbearable’
“Earlier, April and May were the most intense months. Now, the heat starts from January itself. By noon, the roads feel unbearable, and sitting inside the auto is like being inside a pressure cooker. We can’t stop working because of the heat, so we just have to manage somehow,” says K R Vijayan, an autorickshaw driver.
Mani, a security guard at a shop, points to a similar problem. “We have to stand outside the whole day with no proper shade. The heat keeps building, and by afternoon, you feel completely worn out. There is no fixed break, no place to cool down, but we still have to stay there till duty ends,” he says.
The science
Explaining the trend, Vijayakumar P, assistant professor at the University of Kerala, points to the combined effect of rising temperatures and humidity.
“The Arabian Sea is warming, which increases evaporation. At the same time, higher atmospheric temperatures allow the air to hold more moisture. This leads to higher humidity levels, especially in coastal regions, which significantly increases heat stress,” he says.
“Normally, when humidity is low, sweat evaporates and helps cool the body. But when humidity is high, this process becomes inefficient. The body cannot cool itself properly, and the heat feels much more intense,” he explains.
He notes that Kerala used to have a natural pattern that helped regulate summer heat.
Typically, after four to five days with high temperatures in mid-March, summer showers would occur. This acted as a self-regulating mechanism, bringing down the temperature. That balance is now changing.
“Rainfall is becoming more localised and inconsistent. As temperatures rise, the threshold required to trigger rainfall also increases. More moisture is needed in the atmosphere before rain can occur,” he adds.
He also highlights the role of wet-bulb temperature, a key indicator of heat stress.
“Wet-bulb temperature reflects the combined effect of heat and humidity. Studies show that it is increasing across India’s coastal regions. Even if the ambient temperature does not rise significantly, higher humidity can make conditions more uncomfortable and stressful for the human body,” he notes.
Changing cityscape
While the immediate trigger may lie in weather patterns, the intensity of the heat is also tied to the way the city has changed over the years.
Thiruvananthapuram has seen a steady rise in built-up areas from 13% to 41% over the past 30 years. These shifts have contributed to a rise in land surface temperature, which has increased by 4.84°C between 1988 and 2022.
Researchers warn that this is not just about discomfort, but also about vulnerability. Parts of the district have already been identified as highly susceptible to heat stress.
IMD’s senior meteorologist Neetha K Gopal explains the weather factors.
“We may not experience heatwave conditions this summer. However, temperatures are now consistently on the higher side of normal, which is why we are issuing warnings for hot and humid conditions,” she adds.
On the outlook, she says, the current conditions are likely to persist. “Data shows a clear increase in temperatures over Kerala. We are now living in a period of higher temperatures, and above-normal conditions are likely to become more frequent in the future,” she adds.
“We need to get used to this intense heat from now on.”
Keep your rooms cooler:
The right curtains
Use light-colours like white, beige or pastels. Thick cotton or linen fabrics are ideal as they don’t block airflow. Blackout curtains are even more effective for west-facing windows.
Proper ventilation
Keep windows and curtains closed between 10am and 5pm. Open them during early morning and after sunset for cross ventilation.
Cut down heat sources
Turn off the lights, chargers and any other appliances when not in use. Cook early in the morning or later in the evening. Keep kitchen windows open.
Use breathable fabrics
Use cotton bedsheets, pillows and cushion covers. Avoid synthetic materials as they trap heat and make rooms warmer.
Grow indoor plants that cool the air
Plants such as the areca palm, aloe vera, snake plant and money plant help reduce the temperature. Place them near windows or areas that heat up faster.
Natural shading
Let vines like money plant, bougainvillaea, or ivy grow on balconies or window grills. They can filter direct sunlight.
Evaporative cooling
Spray water to lightly dampen curtains or mop floors in the evening. The evaporating water will cool the surrounding air and help regulate the temperature of the room.
Key guidelines
Those working outdoors should reschedule work to early mornings or evenings.
Drink plenty of water, even if you do not feel thirsty, to prevent dehydration.
Salted rice water, buttermilk, and lemon water are recommended.
Drink only boiled and cooled water.
Ensure children are given water frequently.
Avoid or limit highly sweetened and carbonated drinks.
Extra caution is needed for children, the elderly, pregnant women, and those with serious illnesses.
While stepping out
Use footwear, umbrellas, or hats for protection.
Eat water-rich fruits like watermelon and oranges, and include fresh salads.
Do not leave children or elderly people inside parked vehicles under the sun.
Ensure pets and birds have access to water.
With inputs from Supriya