Deficit rains trigger abnormal increase in mercury levels in hills too

CHENNAI: Hill stations in Tamil Nadu are now witnessing an unusual increase in maximum temperature, thanks to the prevailing heat across Tamil Nadu. Ooty, Kodaikanal, Yelagiri and Coonoor are now witnessing simmering heat, and all-time hottest days are being recorded.

The abnormal surge in maximum temperature is recorded in Ooty and Coonoor weather stations, despite the mercury level staying normal in the first week of April. Though Ooty weather station recorded the lowest maximum in the state, from April 28 to May 1, the hill station recorded the all-time highest temperature of 29 degrees Celsius since 1951, which was 28.5 degrees Celsius. The temperature has increased by 5.4 degrees Celsius than usual.

"The hilly regions usually record around 24 degrees Celsius and 25 degrees Celsius during summer seasons. Various reasons such as less moisture, unfavourable wind patterns, and dry soil have led to heat wave conditions prevailing across the state this year, unlike the previous summer seasons, " explained P Senthamarai Kannan, Director of Area Cyclone Centre, Regional Meteorological Centre (RMC), Chennai.

Tamil Nadu has not received summer rain this year due to the impact of El Nino prevailing during the northeast monsoon season in 2023. The year followed by El Nino, the ocean usually absorbs heat earlier and gradually releases it, eventually making it hotter than normal on land.

Various parts of the state, especially the north interior and coastal districts of Tamil Nadu, witnessed a surge in the maximum temperature by 3 to 5 degrees Celsius, considering it a severe heat wave condition. Erode district reported temperatures above 40 degrees Celsius for 27 days. Followed by Karur for 22 days, Tirupathur and Salem districts for 19 days, according to RMC data. The state witnessed a 74 percent deficit in rainfall from March 1 to May 3 during the summer as the soil moisture has reduced.

Despite summer spells predicted across the state for the next few days, the relief from the scorching heat might be temporary as the maximum temperature might decrease only by two degrees Celsius. However, many districts might face soaring heat again as temperature is predicted to rise in the second half of May.

"After the northeast monsoon 2023, the state did not receive rain like the previous years, which resulted in a drastic surge in the maximum temperature. Many places will receive convectional rainfall in the coming days, and it will bring down the mercury level, especially over the hill regions, including Ooty and Kodaikanal, which experienced an abnormal increase in the maximum temperature in April," commented K Srikanth, an independent weather blogger.

Similarly, the weather expert stated that the moisture has completely dried, leading to temperatures shooting up across the state, specifically over hill regions and interior areas. Unlike in previous years, the summer started earlier this year, and three more months are left before the summer season ends.