May was the hottest month in the last five years in Chennai and Bengaluru, according to analysis of Indian Meteorological Department data. This is amid the Ministry of Earth Sciences agency’s warning of heat-related discomfort in the Southern and Konkan regions of the country.

On May 16, Chennai recorded a temperature of 42.7°C. This, according to the IMD, is 4.3°C above normal. Time-series data from IMD indicate that previously mercury reading exceeded this number in May in Chennai in 2017. On May 19, 2017, Chennai recorded a temperature of 43.6°C. However, on no other days in May in the consecutive years did the city record a temperature this high.

Bengaluru, which is otherwise well-known for its cool weather, recorded 35.5°C on May 18. According to IMD data, this was hotter than all the hottest days recorded in the city since 2018. However, on May 8, 2017, the city recorded a temperature of 37°C. IMD does not provide data on the hottest days in May 2019 and May 2020 in Bengaluru.

“(The high temperature) is interesting and unique. We are in the second half of May, but Chennai recorded a temperature higher than Delhi’s this month,” said RK Jenamani, a senior scientist at IMD. “We consider this the season’s highest temperature so far,” he added.

On May 13, 2023, Delhi recorded 43°C. That was the hottest day of the month in the city, as of May 19, 2023. However, that was the coolest hottest day in the city in the last 10 years. In May 2022, the city saw the temperature rise up to 47.2°C. In Mumbai, too, the hottest day of the month saw the temperature rise to 33.9°C. This was cooler than all summers since 2012.

Recently, a report released by the World Weather Attribution, also acknowledged this rise in temperature, which has been happening since April. “These extreme temperatures, combined with humidity, caused a sudden increase in heat stroke cases, roads melting and a strong surge in electricity demand,” it noted.

On the brighter side, predictions say temperature may go down in Chennai and Bengaluru in the coming week.