East India faced life-threatening heat stress in June, say experts

Large parts of eastern India saw a prolonged heatwave in June when experienced temperatures were high enough to be life threatening, experts said. Parts of Bihar and West Bengal experienced continuous heatwaves for 19 and 17 days, respectively, in June, according to the India Meteorological Department (IMD).

- Jayashree Nandi

Bihar recorded a heat index of 50 to 60 degree Celsius during this period. West Bengal would have seen similar values on the heat index as meteorological factors in both places such delayed monsoon and high humidity were similar. The conditions were deadly with the potential to kill thousands of vulnerable people, experts said.

Though relatively lower number of heatwaves in April and May kept focus away from heat stress in the country, climate scientists said June's extreme heat in eastern India should be taken as a warning. In June, Odisha, coastal Andhra Pradesh, Jharkhand and Chhattisgarh also recorded nine to 14 heatwave days.

"Bihar recorded a heat spell from May 30, which continued till June 22. Bhojpur district and the region around Arrah recorded the highest maximum temperature of 45.3 degrees. The heatwave pockets recorded maximum temperatures in the range of 40 to 45 degrees, with humidity ranging from 37% to 47%," said Ananda Shankar, a scientists that the weather bureau's Bihar office.

Maximum temperature of 40 degrees with 47% humidity translates to so-called "feels like" temperature or heat index of 53 degrees; a maximum temperature of 45 degree with humidity of 37% translates to a heat index of 60 degree, according to the US National Oceanic and Atmospheric Administration's heat index calculator.

Total heatwave events this summer from March to June was 218 days over the country, the Met department said. It was the highest in the past 23 years after 2019, with 578 such days and 2022 with 455 days. Most heatwave days were reported in June, with parts of eastern India recording 11 to 19 heatwave days.