T.N. records highest Southwest monsoon temperatures in the last nine years

Tamil Nadu experienced unusually warm weather during the Southwest monsoon this year, with temperatures remaining elevated for a sustained period, according to an analysis by the Regional Meteorological Centre (RMC).

The State recorded its highest temperatures during the season compared with the 2018-25 period. This assumes significance particularly against the backdrop of 2023, 2024, and 2025 being the three warmest years on record globally.

According to the Regional Weather Forecasting Centre (RWFC), RMC, the State registered a mean temperature of 29.45°C during the season (between June and September) this year, which is nearly 1.21°C above the 2018-25 average. The assessment of temperatures during Southwest monsoon showed a sustained period of above readings across the State’s weather stations network.

Both maximum and minimum temperatures remained above the 2018-25 average, with the strongest warming signal observed between July and September. The maximum mean temperature was 34.25°C, with an anomaly of 1.40°C compared to the 2018-25 average. The mean minimum temperature was 24.64°C (+1.02°C).

V.R. Durai, Head, RWFC, said it was not just isolated hot days in different locations, but elevated temperatures persisted over the months. This season’s mean temperature was 0.72°C higher than the previous highest temperature recorded in 2023. “We found that Tamil Nadu recorded a marked rise in mean temperature this season compared with each of the previous years,” he said.

The warming trend strengthened from July this year, after widespread rainfall in June helped keep temperatures under control. This year’s July, August, and September were the warmest months compared to corresponding months in the 2018-25.

Vellore, Puducherry, Palayamkottai, Meenambakkam in Chennai, Kodaikanal, and Tiruttani were among the weather stations that recorded above normal mean temperatures during the Southwest monsoon. The weather station-wise assessment also showed that the warming weather trend was widespread across the State’s network.

Citing the three warmest years globally, Mr. Durai said the trend pointed to an overall warming of weather conditions with every passing year. The spike in temperatures had intensified since 2020. While global warming was a major factor behind the soaring mercury level in the State during the Southwest monsoon, a strong El Niño this year also contributed to the increasing warm trend.

The table shows the average temperature recorded in Tamil Nadu during the Southwest monsoon between 2018 and 2026