# MV Bureau
Kochi | Kerala’s coastal districts are increasingly at risk of dangerous humid heatwaves during breaks in the summer monsoon, a new study has warned.
The research, led by scientists at the University of Reading and published in Climate Dynamics, found that these regions were experiencing rising heat stress not merely from temperature but a dangerous combination of heat and high humidity.
Unlike typical heatwaves, humid ones make it harder for the human body to cool down. High moisture in the air prevents sweat from evaporating, increasing the risk of overheating, heart strain and heatstroke, even when temperatures are not extremely high.
“Kerala’s coastal districts are more prone to humid heatwaves during the summer monsoon compared to inland areas. The risk increases significantly during monsoon break phases,” said Dr Akshay Deoras, lead author of the study.
The study uses “wet-bulb temperature,” combining heat and humidity, to measure the severity of these events. Higher wet-bulb temperatures indicate conditions where sweating becomes ineffective in cooling the body, sharply increasing the risk to human health.
Researchers say these events can be predicted up to four weeks in advance, giving authorities time to prepare. Measures suggested by the study include increasing healthcare readiness, opening cooling centres, adjusting school hours and ensuring stable power supply during peak demand times.
The findings are based on 84 years of data from 1940 to 2023, including the hourly ERA5 global dataset and rainfall records from the India Meteorological Department. Researchers examined 261 active monsoon phases and 188 break periods to track changes in humid heatwave risk.
The study was conducted in collaboration with the University of Leeds, the Met Office and the Indian Institute of Tropical Meteorology.
Scientists say the findings highlight low public awareness about humid heatwaves, which can be more dangerous compared to dry heatwaves which are widely understood across India.
